Before we can make the determination concerning the “who & what” question; what needs to be established is the “why, where & how” facts from scripture.
2 Kings 17:3 (KJV)
3 “Against him came up Shalmaneser king of Assyria; …” name means fire worshiper
2 Kings 17:20-23 (KJV)
20 And the LORD rejected …….. 21 For he rent Israel from the house of David; and they made Jeroboam the son of Nebat king: and Jeroboam drave Israel from following the LORD, and made them sin a great sin. 22 For the children of Israel walked in all the sins of Jeroboam which he did; they departed not… ….So was Israel carried away out of their own land to Assyria unto this day.
Rebellious Israel replaced by many more wicked nations into Samaria!
2 Kings 17:24 (KJV)
24 And the king of Assyria brought men from Babylon, and from Cuthah, and from Ava, and from Hamath, and from Sepharvaim, and placed them in the cities of Samaria instead of the children of Israel: and they possessed Samaria, and dwelt in the cities thereof.
The reader needs to grasp this fact; when the returning exiles arrived in Jerusalem, the transplanted Babylonian peoples had taken control of the land of Israel!
Returning Israel under the governance of a man appointed by Cyrus!
Ezra 1:7-11 (KJV)
7 Also Cyrus the king brought forth the vessels of the house of the LORD, which Nebuchadnezzar had brought forth out of Jerusalem, and had put them in the house of his gods; 8 Even those did Cyrus king of Persia bring forth by the hand of Mithredath the treasurer, and numbered them unto Sheshbazzar, the prince of Judah. 9 And this is the number of them: thirty chargers of gold, a thousand chargers of silver, nine and twenty knives, 10 Thirty basons of gold, silver basons of a second sort four hundred and ten, and other vessels a thousand. 11 All the vessels of gold and of silver were five thousand and four hundred. All these did Sheshbazzar bring up with them of the captivity that were brought up from Babylon unto Jerusalem.
Ezra 5:13-16 (KJV)
13 But in the first year of Cyrus the king of Babylon the same king Cyrus made a decree to build this house of God. 14 And the vessels also of gold and silver of the house of God, which Nebuchadnezzar took out of the temple that was in Jerusalem, and brought them into the temple of Babylon, those did Cyrus the king take out of the temple of Babylon, and they were delivered unto one, whose name was Sheshbazzar, whom he had made governor;
15 And said unto him, Take these vessels, go, carry them into the temple that is in Jerusalem, and let the house of God be builded in his place.
16 Then came the same Sheshbazzar, and laid the foundation of the house of God which is in Jerusalem: and since that time even until now hath it been in building, and yet it is not finished.
Sheshbazzar; his name means worshiper of fire! The reader needs to comprehend this fact; the kings that had taken Israel into captivity and the governor placed in charge of those returning from exile; had similar meaning names that were not of Hebrew dialect! Cyrus had placed in charge an individual not appointed to do so according to guidelines set forth in scripture, but allowed by The Almighty! What we are seeing here is thought provoking!
Then we hear of Jesus The Messiah confronting the very “Transplanted Jews” about their lineage!
John 8:32-33 (KJV)
32 And ye shall know the truth, and the truth shall make you free.
33 They answered him, We be Abraham's seed, and were never in bondage to any man: how sayest thou, Ye shall be made free?
John 8:43-44 (KJV)
43 Why do ye not understand my speech? even because ye cannot hear my word. 44 Ye are of your father the devil, and the lusts of your father ye will do. He was a murderer from the beginning, and abode not in the truth, because there is no truth in him. When he speaketh a lie, he speaketh of his own: for he is a liar, and the father of it.
John 8:47-48 (KJV)
47 He that is of God heareth God's words: ye therefore hear them not, because ye are not of God. 48 Then answered the Jews, and said unto him, Say we not well that thou art a Samaritan, and hast a devil?
The first martyr for The Gospel!
Acts 7 The preaching of Stephen is a direct testimony and reference to the dispersion of Israel sent to Babylon. He later implicates them just as did Jesus The Messiah in John 8, etc.!
Paul addresses the issue in his epistles!
Romans 2:28-29 (KJV)
28 For he is not a Jew, which is one outwardly; neither is that circumcision, which is outward in the flesh: 29 But he is a Jew, which is one inwardly; and circumcision is that of the heart, in the spirit, and not in the letter; whose praise is not of men, but of God.
Romans 9:6 (KJV)
6 Not as though the word of God hath taken none effect. For they are not all Israel, which are of Israel:
2 Timothy 2:19-21 (KJV)
19 Nevertheless the foundation of God standeth sure, having this seal, The Lord knoweth them that are his. And, Let everyone that nameth the name of Christ depart from iniquity. 20 But in a great house there are not only vessels of gold and of silver, but also of wood and of earth; and some to honour, and some to dishonour. 21 If a man therefore purge himself from these, he shall be a vessel unto honour, sanctified, and meet for the master's use, and prepared unto every good work.
Question: What was it about them that made them the synagogue of Satan?
1) Child sacrifice!
2) Their rejection the voluntary gift of life and sacrifice for all mankind; provided by Jesus The Messiah, i.e. The Gospel!
2 Kings 17:29-32 (KJV)
29 Howbeit every nation made gods of their own, and put them in the houses of the high places which the Samaritans had made, every nation in their cities wherein they dwelt. 30 And the men of Babylon made Succothbenoth, and the men of Cuth made Nergal, and the men of Hamath made Ashima,
31 And the Avites made Nibhaz and Tartak, and the Sepharvites burnt their children in fire to Adrammelech and Anammelech, the gods of Sepharvaim. 32 So they feared the LORD, and made unto themselves of the lowest of them priests of the high places, which sacrificed for them in the houses of the high places.
Final considerations: Sounds like abortion to me! Time will tell!