Before one starts to answer the question “ What is the Trinity?” one must first define what Catholics believe about God. As Catholics we believe that God is love. On the other hand the Jews and Muslims believe that God loves, we as Catholics also believe that God loves. But the radical Christian difference is that we believe that “God is love” Thus love is not something that God does, but its who God is. The claim that God is love, is the ground for the Trinity. G.K Chesterton once said that a lot of people are uneasy about the Doctrine of the Trinity, but everybody gets enthusiastic about the claim that God is love, in fact, those two claims are the same. If one says that God is love, you have to mean that within the very being of God there is the play of a lover, a beloved and the love that they share. Yes, God loves the world that is true, but more importantly God is love that there is a play of one, two and three, within the one God of Israel. Something which amazed me was that John, Peter, Paul all of them were proclaiming the God of Israel, thus no Christian for one second denied the unity of God. In the Nicene Creed we reflect about the Trinity, when we say: ”We believe in in one God” Thus the God of Israel revealed himself to have a play of a lover, beloved and love. We know this because Jesus is the Son who was sent by the one he called Father is himself God. Abraham was sent, Isaiah was sent, Jeremiah was sent but they were sent just as human prophets, Jesus was sent, but He is God. Therefore withing God Himself there is the play of sender, sent and the love in which the love was sent, this is the ground for the Christian claim of the Trinity.