Charity is the traditional Christian word for love, and an Act of Charity is an expression of our unselfish love for God. While such a prayer can be as simple as "O God, I love You," the following longer prayer is a traditional version of an Act of Charity.
An Act of Charity
"O my God, I love Thee above all things, with my whole heart and soul, because Thou art all good and worthy of all love. I love my neighbor as myself for the love of Thee. I forgive all who have injured me, and ask pardon of all whom I have injured. Amen."