Having had extensive jail ministry experience, let me say this! Less than 4-5% are really serious.
For some it is something to pass the time!
For others, they want to look good for their Probation Officer or parole board.
The test for many is what are they willing to give to live for God. That has always been a catylist of whether they were going to stay in a religious program.
Most are in there because their selfishness pushed them to crime! If theyhave some true repentance they will begin to shed that selfishness and that only happens through sacrifice. In the prison system that is few and far between. They like salvation, as long as it does not cost them a thing!
A good lesson for a session, possibly somewhere down the road is
John 6.
Just my input!