How could this person stay saved in prison?

[Lost]

We'll assume that this person has been born again according to the Acts 2:38 message, but still has to pay the consequences of being convicted of previous crimes from their pre-Christian days. Their prison term is five to ten years in a low-to-medium security facility, although they are not allowed to leave the prison facilities (road-crews, etc).

They are a prisoner that has only the most minimal personal possessions, and only weekly access to outside visitors (which we will also assume is usually, if not always, local family - spouse, children, etc). There is no prison ministry that teaches Bible truth, as there is no local Apostolic church in the immediate area.

This person was only recently given his prison sentence and you were notified of this by his family. Given the limited info, what would you say to advise this person on how to stay saved? Would you suspect it is even possible?