There is a plethora of verses that say that people can not cause a saved Christian to lose his salvation, such as
John 10:29 (NLT)
for my Father has given them to me, and he is more powerful than anyone else. No one can snatch them from the Father’s hand.
However, this does not exclude the possibility of a Christian choosing to turn away from God, as in
Hebrews 6:4-6 (NLT)
For it is impossible to bring back to repentance those who were once enlightened—those who have experienced the good things of heaven and shared in the Holy Spirit, who have tasted the goodness of the word of God and the power of the age to come—and who then turn away from God. It is impossible to bring such people back to repentance; by rejecting the Son of God, they themselves are nailing him to the cross once again and holding him up to public shame.
So, my question is: is it possible for a saved Christian to choose to walk away from Christ and thus lose their salvation?
A good way to study the issue is by defining the terms in use:
Saved Christian: person depending on Christ and being blessed.
Choose: a situation arises, while depending on Christ, requiring the person to decide if the blessing is still available.
In the OT, Abraham believes God will protect him and obeys His command to leave his birthplace. He learns that God has intervened and saved him from danger in several situations. Finally God asks him to sacrifice his son. Abraham must choose: is God Himself dangerous? Erratic? Inconsistent? Unreliable?
He must chose between depending on his own resources or depending on God. He has seen that depending on himself for results has led to unsatisfactory outcomes (the Abimelech and Hagar incidents) , while when depending on God has always been beneficial. Abraham chooses to depend on God, and his choice is rewarded.
In the NT, Peter believes Jesus will bless him and leaves everything to follow Him. He ”has tasted the goodness of the word of God and the power of the age to come”. But some words are hard to swallow, and some disciples decide to leave:
John 6:66 NET After this many of his disciples quit following him and did not accompany him any longer.
Following Jesus will label Peter a lunatic! What does Peter decide when Jesus asks for a decision?
John 6:68-69 NET Simon Peter answered him, “Lord, to whom would we go? You have the words of eternal life. We have come to believe and to know that you are the Holy One of God!”
What were the factors to be considered by Abraham and Peter?
Were the things they saw same as having ”experienced the good things of heaven and shared in the Holy Spirit”?
Was the god they followed the one true Holy God who was above all things?
Could it be that the command God gave them, which seemed uncharacteristic of a Holy God, actually holy, justifiable in the future, able to reconnect (re-ligare) Man with God, but incomprehensible immediately?
Judas considered these things in differently and left, mentally. He should have left physically, before he was publicly identified. Why did he decide wrong?
John 6:70 NET Jesus replied, “Didn’t I choose you, the twelve, and yet one of you is the devil?”
The one influenced by the devil sees rewarding situations and tries to harness it to forward his unholy ends. Bad call doing it at the celebration of the union of a Holy God with His Holy People:
Matthew 22:11 NET But when the king came in to see the wedding guests, he saw a man there who was not wearing wedding clothes.
God called His own. He gave them to Christ. Christ never lost those who came to Him, because God knew those who really feared Him:
Genesis 22:12 NET “Do not harm the boy!” the angel said. “Do not do anything to him, for now I know that you fear God because you did not withhold your son, your only son, from me.”
Those who were evil, but repented, like Nineveh, could stay. They believed Jesus, abided in Him and were cleansed:
John 15:3 NET
You are clean already because of the word that I have spoken to you.
Those who wavered left room for the devil to enter:
John 13:10 NET
Jesus replied, “The one who has bathed needs only to wash his feet, but is completely clean. And you disciples are clean, but not every one of you.”
Those who stayed and tried to further their selfish ends were judged and served as a negative example.
Acts 5:13-14 NET None of the rest dared to join them, but the people held them in high honor. More and more believers in the Lord were added to their number, crowds of both men and women.
Better to leave before you are found out and used as a vessel of dishonour, meet for ignoble use.
The devil can't take you, because God is stronger. All He requires is your unforced decision, not your performance. Good thing, that...
Luke 22:31-32 NET “Simon, Simon, pay attention! Satan has demanded to have you all, to sift you like wheat, but I have prayed for you, Simon, that your faith may not fail. When you have turned back, strengthen your brothers.”
Before the host comes around to welcome the wedding guests, they must decide to commit or not:
Luke 14:32 NET 32 If he cannot succeed, he will send a representative while the other is still a long way off and ask for terms of peace.