What does Luke 23:39-43 say to readers about the concept of salvation?

In the Gospel of Luke, verses 23:39-43, reports a scene where while nailed to the cross, Jesus had an interaction with the two criminals that were crucified along side of him. One of the criminals said, “If you’re truly a God, save yourself and save us as well.” The other criminal said to the first, can’t you see that this man is innocent? We deserve to be crucified but Christ does not.” The repentant criminal then said to Jesus, “Remember me when you comest into thy kingdom.” Christ then said to the repentant criminal, “Verily I say unto thee, Today shalt thou be with me in paradise.” To me, this verse shows that faith in God, and his son, Jesus Christ are the only ways to salvation and that there are free and open blessings to those who approach him sincerely. It also indicates that divine ideas of justice and salvation, are different than earthly ideas of justice and salvation. The criminal who repented no doubt committed an offense to the State that mandated his execution; however the Bible shows that Jesus Christ, still displaying his divine nature, forgave the criminal, and promised him a home in Heaven.