Hebrews 6:4-6 I only use this to show that one could leave the faith,,,not to show that they cannot return...We could discuss.
Hebrews 6:1-9 KJV
1) Therefore leaving the principles of the doctrine of Christ, let us go on unto perfection; not laying again the foundation of repentance from dead works, and of faith toward God,
2) Of the doctrine of baptisms, and of laying on of hands, and of resurrection of the dead, and of eternal judgment.
3) And this will we do, if God permit.
4) For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost,
5) And have tasted the good word of God, and the powers of the world to come,
6) If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame.
7) For the earth which drinketh in the rain that cometh oft upon it, and bringeth forth herbs meet for them by whom it is dressed, receiveth blessing from God:
8) But that which beareth thorns and briers is rejected, and is nigh unto cursing; whose end is to be burned.
9) But, beloved, we are persuaded better things of you, and things that accompany salvation, though we thus speak.
Firstly, this passage does not actually say, "leave the faith", it says, if they should fall away.
It doesn't say, those who were saved, reborn, justified, raised with Christ, crucified with Christ, I could go on, all these technical and descriptive words used in the Bible to show our salvation, none of them used here.
For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost,
5) And have tasted the good word of God, and the powers of the world to come,
Which if these do not describe all the people Jesus ministered to? Taught? Worked miracles for? Sent out to DO miracles? Tasted the Word, but not eaten it? Shared in what the Holy Spirit did, but not reborn?
This phrase, "the powers of the age to come", the kingdom powers working through Jesus in His ministry.
That ONE unforgivable sin, to declare the work done by the Holy Spirit as being done by an unclean spirit.
Does this apply to NT Christians? One shot at "being saved". If you "get saved" and "screw it up" forget about it, you can't get back?
Or is it more properly placed in a context where the writer to the Hebrews is saying, if you do this kind of rejection after all you've seen and experienced, be warned lest you end up as the Pharisees,
John 12:37-40 KJV
37) But though he had done so many miracles before them, yet they believed not on him:
38) That the saying of Esaias the prophet might be fulfilled, which he spake, Lord, who hath believed our report? and to whom hath the arm of the Lord been revealed?
39)
Therefore they could not believe, because that Esaias said again,
40) He hath blinded their eyes, and hardened their heart; that they should not see with their eyes, nor understand with their heart, and be converted, and I should heal them.
Who is forever rejected? Those who saw His miracles, but believed Him not.
Much love!