Its hard to understand why you should think for a minute that Jesus taught anyone to follow any other god than the God of the Jewish Tanakh (ie the Old Testament). If you can add to your question to show how Jesus's teaching differs from the Tanakh then that would be helpful. As far as the Christian is concerned nothing Jesus taught contradicts the Tanakh, when the Tanakh is rightly understood: if you think it does then please tell us how.
Having said that, the Apostle Paul tells us that what the prophets of the Old Testament promised was that one day would be proclaimed "the gospel" (Romans 1:1,2). Now the gospel is a message. So what was promised was a new message from God. This is confirmed by the prophet Jeremiah:
Behold, the days come, says the LORD, that I will make a new covenant with the house of Israel, and with the house of Judah: not according to the covenant that I made with their fathers in the day that I took them by the hand to bring them out of the land of Egypt .... for I will forgive their iniquities, and I will remember their sin no more. (Jeremiah 31:31-34)
The Apostle Paul further states that this gospel is concerning his Son Jesus Christ our Lord, which was made of the seed of David according to the flesh; and declared to be the Son of God with power, according to the spirit of holiness, by the resurrection from the dead (Romans 1:3,4).
According to NT the resurrection is sufficient proof He is the Son of God
According to the Apostle the resurrection declares Jesus is the Son of God.
The resurrection by itself shows that Jesus is from God, and that everything he said during his life was true, otherwise God would not have given a plain demonstration of his approval of Jesus by raising him from the dead. What the resurrection, by itself, cannot do is demonstrate that Jesus of Nazareth is that promised Messiah of the Old Testament. In order to demonstrate that the resurrection must fulfil the prophesies of it in the Old Testament.
This is my point, the Gospel is not "just" that Jesus is the Son of God: it is that he is the promised Messiah of the Old Testament; and the resurrection, like many other events in the ministry of Jesus, is prophesied in the OT and fulfilled in the ministry of Jesus.
When Paul preached to the Greeks in the midst of the Areopagus at Athens he felt no need to prove his beliefs by any reference to the Old Testament. And he finished his message saying:
The times of this ignorance God overlooked/winked at: but now he commands all men everywhere to repent: because he has set a day, in the which he will judge the world in righteousness by that man whom he has ordained. And of this he has given assurance (some versions say "proof") unto all men by raising him from the dead. (Acts 17:30,31)
The Old Testament, then, is not necessary to prove the resurrection, Paul made no use of it in his sermon. But the resurrection must not contradict the OT, as Isaiah says:
To the law and to the testimony: if they speak not according to this word it is because there is no light in them (Isaiah 8:20).
It is not correct to claim that "In and of itself, the resurrection proves nothing. You must bring independent proof from outside the New Testament so as no to be guilty of circular logic." Paul brought no evidence from the OT. If it is circular logic to restrict to the NT alone then why isn't it circular logic to restrict to NT and OT alone? The NT has sufficient evidence within itself to prove it is the Word of God. But as Isaiah 8:20 shows what is needed is to show that the resurrection, and the NT and the OT all agree together, that the NT does not contradict the OT.
NT and OT are two witnesses
We do not have the NT as a solitary witness for the messiahship of Jesus of Nazareth, we have the OT also as an independent witness, that out of the mouth of two or three witnesses everything might be established (Deuteronomy 19:15, Matthew 18:16). And in that the Jews in the main reject Jesus of Nazareth as their Messiah, the witness of the Tanakh is strengthened because there has obviously been no collusion between Christians and Jews in the making or preservation of the OT, seeing the two peoples oppose each other in this matter. The OT and the NT are thus two witnesses which are entirely independent.
Resurrrection is no proof to the rebellious
Of course, the resurrection is no proof to those who do not want to believe: nothing is. Jesus ended one of his parables with a man claiming:
"'But if someone goes to them from the dead then they will repent.' But he said to him 'If they will not listen to Moses and the prophets, neither will they be persuaded even if someone should rise from the dead'" (Luke 16:30,31).
Resurrection in the Tanakh/ Old Testament
Jesus brings us to the same God, because he, his death, and his resurrection fulfil the prophesies of the Tanakh:-
The resurrection is found in many places in the Tanakh such as here:
After two days will he revive us, in the third day he will raise us up, and we shall live in his sight. Then shall we know, if we follow on to know the LORD... (Hosea 6:2,3).
Just as it was through suffering, the loss of a rib, that Adam gained a bride, so through suffering the Messiah would gain his Bride.. all those who would believe on him. And as Adam was raised out of his sleep to enjoy Eve, so Christ was raised out of death to delight in his Bride. And Eve was made because it was not good that man should be alone (Gen 2:18) because man was made in the image of God (Gen 1:26), from which we conclude that there is more than one person in the Godhead.
The Gospel according to Moses
In the last fourteen chapters of Genesis, chapters 37 to 50, we have the life and ministry of Joseph. He was envied by his brothers (Genesis 37:11, Matthew 27:18), the children of Israel, because he was the favourite of his father; because they envied him they sold him for 20 pieces of silver into slavery (27:28, Matthew 26:15); by this, in a figure, they killed him so that Jacob said "Joseph is without doubt rent in pieces" (37:33). When Joseph was 30 years old (41:46, Luke 3:23) he was raised from the prison and he was elevated to the second highest position in Egypt (41:40, Matthew 28:18, 1 Corinthians 15:24-28); and Joseph used his position of power, not to get revenge on his brothers but, to save all the children of Israel from death. And when their father died Joseph's brothers came trembling to him for mercy: what Joseph said could equally come from the mouth of Jesus, "But as for you, you thought evil against me, but God meant it for good, to bring to pass, as it is this day, to save much people alive. Now therefore, fear ye not: I will nourish you and your little ones. And he comforted them and spake kindly to them." (Genesis 50:20,21). The life of Joseph is a true history but it is also a gospel allegory, including salvation for the people of God by a figurative death and resurrection.
The Gospel according to Mordecai
The book of Esther is also the gospel in the form of an allegory. Just as Esther saved her people, the Jews, by her willingness to die, saying if I perish, I perish (Esther 4:16), so Christ saves his people by actually dying. As she suffered having requested that the Jews of Shushan neither eat nor drink for three days, night or day and promising I also and my maidens will fast likewise (Esther 4:16) and afterwards went into the secret place to intercede for her people, so Christ also suffered and was in the grave three days and three nights before his ascension to intercede in Heaven for his people. And just as Esther was related both the to the Jews and the King (by marriage), so Christ is related both to us, being made a man, and to the Father, being of the same nature, God made flesh. And just as Esther had neither mother nor father, so Christ had neither father nor mother, his human nature having no human father, and his divine nature having no divine mother. It was not the worthiness of the Jews that delivered them, rather it was the beauty of Esther; and it is not our worthiness that saves us, rather it is the spotless beauty of our Messiah.
A gospel allegory in the book of Samuel
In the book of Samuel we have another picture of the resurrection. David is in a lot of trouble, his men are threatening to kill him, after he and his men return to Ziklag on the third day (1 Samuel 30:1) to discover that all their wives and children have been taken captive. But David and the people are all delivered in an unexpected way: a stranger whose name we even do not know, a suffering servant, who was despised and rejected, is brought back from the edge of death, when they gave him something to eat and drink his spirit came again to him: for he had eaten no bread, nor drunk any water, three days and three nights (1 Samuel 30:12,13). (The word "spirit came again" (KJV) probably means his "breathing returned to normal", his breathing had been very shallow, he was very close to death.) It was through this man, and through what this man said, that deliverance came. The same with Jesus of Nazareth: even though he might have seemed to be a nobody and a stranger to the Jews, yet it is through his resurrection, and the Gospel message that he gives, that deliverance comes to those who believe in him.
In summary notice that in each of the three above examples not a single life was lost, every single one that was in trouble was delivered in each story.
Pictures from the OT
When Adam and Eve sinned God promised them a Saviour, Genesis 3:15, who would bruise Satan's head but be bruised in the heel himself in the process. It was by faith in this promise of God that those before the time of Abraham were able to be saved, and call upon the name of the LORD (Gen 4:26).
Abraham was promised that this Saviour would be one of his descendants. And Abraham believed God's promises and this was what made Abraham righteous before God. And, as a token of the covenant He made with Abraham, God gave him the sign of circumcision to him and his descendants. God was pleased with Abraham because of Abraham's faith which he had before he was circumcised: Abraham believed God and He accounted it to him for righteousness (Gen 15:6). Circumcision, then, should act as a reminder of how Abraham pleased God.
David was promised one of his descendants would sit on his throne forever:
And when thy days be fulfilled, and you shall sleep with your fathers, I will set up your seed after you, which shall proceed out of your bowels, and I will establish his kingdom. He shall build a house for my name, and I will establish the throne of his kingdom forever. (2 Samuel 7:12-13).
This King would be from David's own body. He would live forever. No one today, in fact no one since the destruction of the Jewish public records in Jerusalem by the Romans (in either the first of second century), can actually prove they are a descendant of David.
David prophesied: The stone the builders rejected has become the head of the corner (Psalm 118:12) i.e. the builders are the Jewish religious authorities: the one rejected by them would be the Messiah.
And David prophesied that the Messiah would be resurrected physically soon after death:
Therefore my heart is glad, and my glory rejoices, my flesh also shall rest in hope. For you will not leave my soul in Sheol, neither will you let your Holy One see corruption [bodily decay]. Psalm 16:10
Isaiah tells us that a virgin will conceive and bear a son and his name shall be called Immanuel which means 'God with us' (Isaiah 7:14).
Isaiah also tells us a child will be born And his name will be called... Mighty God (Isaiah 9:6).
Isaiah also prophesies:
He is despised and rejected by men, a man of sorrows and acquainted with grief. And we hid as it were our faces from him; he was despised, and we did not esteem him.
Surely he has borne our griefs and carried our sorrows; yet we esteemed him stricken, smitten of God and afflicted.
But he was wounded for our transgressions, bruised for our iniquities; the chastisement of our peace was upon him and with his stripes we are healed.
All we like sheep have gone astray, we have turned ereryone to his own way; And the LORD has laid on him the iniquity of us all.
He was oppressed and he was afflicted, yet he opened not his mouth; he was led as a lamb to the slaughter, and as a sheep before its shearers is silent so he opened not his mouth.
He was taken from prison and from judgement, and who will declare his generation (offspring)? For he was cut off from the land of the living; for the transgression of my people was he stricken.
And they made his grave with the wicked - but with the rich in his death, because he had done no violence, nor was any deceit in his mouth.
Yet it pleased the LORD to bruise him; he has put him to grief. When you make his soul an offering for sin, he shall see his seed, he shall prolong his days [ie he shall be resurrected after his suffering], and the pleasure of the LORD shall prosper in his hand. He shall see the travail of his soul [ie he shall see the souls saved as a consequence of his death, because he will be resurrected] and be satisfied.
By his knowledge my righteous servant shall justify many, for he shall bear their iniquities.
Therefore will I divide him a portion with the great, and he shall divide the spoil with the strong, because he poured out his soul unto death, and he was numbered with the transgressors, and he bore the sin of many, and made intercession for the transgressors. (Isaiah 53:3-12)
Isaiah also tells us what God said to his Messiah:
It is too small a thing that you should be my servant to raise up the tribes of Jacob, and to restore the preserved ones of Israel; I will also give you to be a light to the Gentiles; that you should be my salvation to the ends of the earth (Isaiah 49:6).
And David prophesies, speaking of the Messiah's death:
They have pierced my hands and my feet (Psalm 22:16).
This reading is the reading of Psalm 22:16 in the Dead Sea Scrolls. The Hebrew of the Masoretic Text translates as "Like a lion are my hands and my feet", which makes very little sense. Either the text was changed to "they have pierced" before the time of Christ or the Masoretic Jews changed it to "like a lion" sometime between 100 BCE and 1000 CE. The Christian view makes most sense, the Jews changed it because they didn't like "they have pierced my hands and my feet" because it points to Jesus of Nazareth as the Messiah.
Early in this long post reference was made to Jeremiah who had said that when the Messiah comes a new covenant will be made by God, not like the covenant made with them when He brought them out of Egypt, in which the LORD says I will forgive their iniquity and remember their sin no more (Jeremiah 31:31-34). Now if God has forgotten the sins of his people then why do they need to continue offering sacrifices? The implication of this is that the sacrificial system with its bulls and goats, etc, will no longer be needed. This is the argument of the author of the letter to the Hebrews 10:1-18, especially 10:16-18.
Daniel tells us that after the Messiah has come the city [of Jerusalem] and the Temple will be destroyed, and this shall be until the consummation [until the day of judgement] (Daniel 9:26-27). In other words the Temple will never be rebuilt: the sacrificial system of the Tanakh is no longer needed because the True Sacrifice, the Messiah, has been sacrificed. As you know the Temple in Jerusalem was destroyed in 70 CE. So we need to find the Jewish Messiah before 70 CE.
Daniel tells us the Son of Man shall come in the days of the Empire of iron, the Roman Empire (Daniel 7:13,14).
In fact, Daniel tells us that 490 years after a decree to rebuild Jerusalem shall six very important things happen (Daniel 9:24). The decree of Artaxerxes (in Ezra 7) was given in 458 BCE. And 490 years after 458 BC is 33 C.E. when Christ was crucified; (there was no year zero).
In 1942 Parker and Dubberstein published their book "Babylonian Chronology, 626 B.C. to A.D. 45" which has become the standard work on chronology for the period. In that work the dates for every new moon were recorded using Julian Calendar dating. The date for the departure of Ezra on the first of Nissan 458 B.C. is recorded in their book as 8th April 458 B.C.
Recently, Rodger C. Young (rcyoung.org) and Pastor Steve Rudd (www.bible.ca) have made the valuable discovery, that changing this date to the astronomically accurate Gregorian Calendar produces 3rd April 458 B.C. which is 490 years to the resurrection on 3rd April 33 CE (Gregorian) to the exact day. If this is the intended interpretation then Daniel 9:24 is not directly pointing to the crucifixion: rather, it is pointing to the resurrection, as the sign demonstrating the efficacy of the crucifixion. (33 CE is one of the few possible years of the crucifixion because in that year Passover fell on a Friday.)
Finally, after three days and three nights Jonah was spewed out of the great fish/whale (Jonah 1:17). He then went to Ninevah to tell them that in 40 days they were going to be destroyed. It is not correct to say he told them to repent. They asked him how he smelt so bad of fish, and maybe why he looked so strange, having been in a fish's belly for three days. He told them what had happened to him and why he had been in the fish... because of his rebellion against his God. We know the Ninevites learned these things about Jonah because Jonah was a sign to the Ninevites (Luke 11:30), meaning a sign of death and resurrection.
The Ninevites said: "We are in big trouble. Yet Jonah found mercy at the last hour by his repentance. It won't do us any harm to repent either. Who knows? Maybe God will have mercy upon us too, even though God has not promised mercy upon our repentance." So they repented, and God relented. For the Jews, it is the eleventh hour: but God, the God of Abraham, Isaac and Jacob, offers forgiveness upon your faith in Jesus Christ and repentance back to God.
Jesus of Nazareth fulfils Daniel 9:26: he came before the destruction of the Temple. He fulfils Isaiah 49:6 because he is worshipped throughout the world as the Messiah. And he fulfils 2 Samuel 7:13,14 - he is a descendant of King David both through his mother (Luke's Gospel) and through his adopted father (Matthew's Gospel).
Both Luke and Matthew must have examined the public records in Jerusalem showing the ancestry of Jesus: the only thing Jesus's enemies, the Jewish religious authorities, had to do to show Jesus was not the promised Messiah was to demonstrate from those records that he was not a descendant of David. In that they never made that claim, and we instead only hear a deafening silence from them in this matter, then a very likely scenario is that they did indeed examine those public records and found precisely the same evidence as that found by Matthew and Luke.
Jesus of Nazareth is the Messiah of the Tanakh, he rose from the dead the third day as the Tanakh prophesied.