Catechism of the Catholic Church

Jesus gave scandal above all when he identified his merciful conduct toward sinners with God's own attitude toward them. He went so far as to hint that by sharing the table of sinners he was admitting them to the messianic banquet. But it was most especially by forgiving sins that Jesus placed the religious authorities of Israel on the horns of a dilemma. Were they not entitled to demand in consternation, "Who can forgive sins but God alone?" By forgiving sins Jesus either is blaspheming as a man who made himself God's equal or is speaking the truth, and his person really does make present and reveal God's name. (431, 1441, 432)