"You are merciful to all, for you can do all thing"
God is the Father Almighty, whose fatherhood and power shed light on one another: God reveals his fatherly omnipotence by the way he takes care of our needs; by the filial adoption that he gives us ("I will be a father to you, and you shall be my sons and daughters, says the Lord Almighty"): finally by his infinite mercy, for he displays his power at its height by freely forgiving sins.
Source: Catechism of the Catholic Church (Vatican.va)