Leo Tolstoy said this quote

It became clear to him that all the dreadful evil he had been witnessing in prisons and jails and the quiet self-satisfaction of the perpetrators of this evil were the consequences of men trying to do what was impossible; trying to correct evil while being evil themselves...Now he saw clearly what all the terrors he had seen came from, and what ought to be done to put a stop to them. The answer he could not find was the same that Christ gave to Peter. It was that we should forgive always an infinite number of times because there are no men who have not sinned themselves, and therefore none can punish or correct others.