If the man is not going to rape any more children, why should he be put in jail? If he will continue to, of course he should be put in jail. A punishment is useless if it makes no difference to society.
I almost threw up after reading your comment. Religious nuts like you are really a horrendous bunch. The man has to pay for his crimes. It is not like you can rape three dozen girls and then walk home saying that you are not going to repeat the crime.