Whether it is orthodox, protestant, evangelical, or catholic Christianity, all agree on the doctrine that God exists as three persons–Father–Son–Holy Spirit together as one God.
Below is a brief outline of the primary Scriptures that described the doctrine of the Trinity.
Definition of the Trinity
I believe that the one God exists as three distinct persons—Father, Son, and Holy Spirit—each is equal in nature, equal in glory, but distinct in relationship (definition based on J. Scott Horrell and his forthcoming book on the Trinity).
II. GOD IS ONE
A. Old Testament
When reading the first five books of the Old Testament it is good to remember who wrote the books, whom they were written to, and what was the historical context of “God” at that time. Numerous hints and evidences are provided in the Bible that suggest Moses was the person who wrote the first five books of the Bible. And those first five books were written between 1446 and 1406 after the “Exodus” of the Israelites from Egypt. In this time, there were numerous gods throughout the ancient near east. Gods of fertility, water gods, grain gods, and many many others. Moses, as God’s chosen leader taking the people out of Egypt recorded the first five books of the Old Testament as a way to communicate to the Israelites who they were and who their God was.
1. Gen 1:1
Simply, one God created the world with ease and freedom.