1 John 3:1-3 KJV
1) Behold, what manner of love the Father hath bestowed upon us, that we should be called the sons of God: therefore the world knoweth us not, because it knew him not.
2) Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when he shall appear, we shall be like him; for we shall see him as he is.
3) And every man that hath this hope in him purifieth himself, even as he is pure.
IF we are the sons of God NOW, when we see Him, we WILL BE like Him.
Who is the son of God who will not be transformed to become like Him? If any of God's children are not made to be like Him when He appears, then this Scripture would be false for them. I believe the Scriptures.
If we are God's children now, we will be like Him then.
Philippians 3:20-21 KJV
20) For our conversation (lit. Citizenship) is in heaven; from whence also we look for the Saviour, the Lord Jesus Christ:
21) Who shall change our vile body, that it may be fashioned like unto his glorious body, according to the working whereby he is able even to subdue all things unto himself.
If we are citizens of heaven now, Jesus will transform us then.
All of these don't allow that someone who is reborn will fail to remain reborn, a child of God.
Again, the wording is plain and clear. You can say, "It's debateable", but I'd want to see the specifics behind that. Because the wording in these passages is clear.
They are either believed or disbelieved.
Much love!