Here are some biblical scriptures that demonstrate how God’s purpose of salvation includes individuals who are/were imprisoned. God’s mercy, forgiveness, and love continue behind prison walls and His Good Word demonstrates this.
“Therefore, there is now no condemnation for those who are in Christ Jesus, because through Christ Jesus the law of the Spirit who gives life has set you free from the law of sin and death. For what the law was powerless to do because it was weakened by the flesh, God did by sending his own Son in the likeness of sinful flesh to be a sin offering. And so he condemned sin in the flesh.” -Romans 8:1-3
“I have told you these things, so that in me you may have peace. In this world, you will have trouble. But take heart! I have overcome the world.”-John 16:33
“Keep on loving one another as brothers and sisters. Do not forget to show hospitality to strangers, for by so doing some people have shown hospitality to angels without knowing it. Continue to remember those in prison as if you were together with them in prison and those who are mistreated as if you yourselves were suffering.” -Hebrews 13:1-3
“The Lord hears the needy and does not despise his captive people.” -Psalm 69:33