“Blessed are the pure in heart, for they will see God”
83. This Beatitude speaks of those whose hearts are simple, pure and undefiled, for a heart capable of love admits nothing that might harm, weaken or endanger that love. The Bible uses the heart to describe our real intentions, the things we truly seek and desire, apart from all appearances. “Man sees the appearance, but the Lord looks into the heart” (1Sam 16:7). God wants to speak to our hearts (cf. Hos 2:16); there he desires to write his law (cf. Jer 31:33). In a word, he wants to give us a new heart (cf. Ezek 36:26). “Blessed are the merciful, for they will receive mercy”
80. Mercy has two aspects. It involves giving, helping and serving others, but it also includes forgiveness and understanding. Matthew sums it up in one golden rule: “In everything, do to others as you would have them do to you” (7:12). The Catechism reminds us that this law is to be applied “in every case”,especially when we are “confronted by situations that make moral judgments less assured and decision difficult”.