An even more basic reason why we are commanded to love is expressed explicitly in Jesus' words, "love your enemies.... that ye may be children of your father which is in heaven." We are called to this difficult task in order to realize a unique relationship with God. We are potential sons of God. Through love that potentiality becomes actuality. We must love our enemies, because only loving them can we know God and experience the beauty of His holiness.

Loving Your Enemies (Christmas 1957)