The late Charles Colson was a criminal. My skeptical friend said he died guilty: once a scoundrel - always a scoundrel.
What about jailhouse conversions?
Sure, some of them are phony or don't last.
The Bible says, "By their fruits you shall know them." It also says many concepts therein are spiritually discerned.
But this one's obvious to any honest person: transformation is possible and is proven every day.
difficult lesson for us is that while God’s grace erases the guilt of
our sin before him, there may be consequences of sin that yet occur in
this temporal realm. Divine forgiveness (desiring and acting for
another’s ultimate good despite their guilt) is not the same as pardon
from all earthly consequences; bank robbers may still need to serve
prison terms even if they become believers. It also helps to have an
eternal perspective in considering that David’s child would still be
with him and the Lord forever in the heavenly kingdom, freed of all
earthly trauma (v. 23)." ESB Study Bible