One BIG problem is not being born again the way the scriptures teach it. Acts 2:38 comes after the listeners of the gospel message preached by Peter (who was taught by Jesus), were “pricked in their heart” (vs 37). What they heard, they believed; for you can’t feel conviction for something you don’t believe. I strongly suspect that the man may have repented at some point, but not baptized in the name of Jesus Christ, nor filled with the Holy Ghost.
Secondly, being born again spiritually puts one in one of the seven churches. All of the saints, in all of the seven churches, are told he “that overcometh”; indicating that there is potential for not overcoming. Not overcoming would seem to be a choice. God is faithful to the faithful. So failure wouldn’t be God’s fault.
Good Comment, Thanks.
John 4:23
But the hour cometh, and now is, when the TRUE worshipers shall worship the Father in spirit and in truth: for the Father seeketh such to worship him.
If there is a class of true worshipers, then there is a class of not-true worshipers. There are quite a few reasons that true believers would decide to fall away — family, peers, porn, yada, yada, yada.
Those Jews in Act 2:38 were convinced by Peter’s sermon to believe that Christ was the Messiah — then, they obeyed Peter’s command to repent and be baptized (and from other verses, we learn they confessed that Jesus is Lord. They worshiped in “truth.”