In this paper I would like to discuss what the Old Testament has to say about the Christian doctrine of the Trinity. I take it as agreed that this task is both important and necessary for a real understanding of the New Testament, which by itself, is neither complete, meaningful nor self-authenticating. I do not make any claims to completeness on this crucial topic, but wish only to suggest what I feel are some important points for consideration. I want to discuss the three persons of the Trinity separately, beginning with the Father, then proceeding to the Holy Spirit and then to the Son. My remarks about the Father will be brief. I only wish to make the point that the Old Testament as well as the new Testament is fully aware of God's Fatherhood and alive to the reality that God loves mankind. It is clear that Israel has a special place as indicated by such passages as Exod. 4.22 where God addresses Israel saying: ‘Israel is my first born son.’ Yet at the same time it is basic to an understanding of Old Testament thought that God is the Father of the other nations of the world, though they are not the ‘first born’. This is a cardinal position of Old Testament theology and is based on the belief, given expression in Genesis, that all belongs to and was created by God.