So many people, so many Christians, ask the simple question: "Where was Jesus in the old testament?"
"How come we only hear about God and the Holy Spirit?"
Jesus was always there, that I can tell you. Let me show you that in the scriptures, just some of the passages. For example, John 1:1 - "In the beginning was the Word, and the Word was with God, and Word was God." and John 1:14 - "And the Word was made flesh, and dwelt among us..."
So, here the Bible talks about the "Word", which is Jesus. The Word, Jesus, was with God in the very beginning, as you can read here. Then Jesus became flesh, meaning he came down as a man.
Jesus was always there, even in the old testament. When you read the old testament, you don't see him as a person, but you see him in the "Word", in Gods word, in the very written words of the old testament.
He was even there in the beginning, check it out:
Genesis 1:26 - Then God said, "Let us make man in our image, after our likeliness..."
Now, why would God say "us"? Because he wasn't alone and he's not alone today. It's the Father, Son and Holy Spirit, as it was in the very beginning.