There is one God and only one God. He is personal and knowable. He manifests Himself in three persons: the Father, the Son and the Holy Spirit.
Deuteronomy 6:4
Hear, O Israel: The LORD our God is one LORD:
Matt 28:19
Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:
I Jn 5:7
For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one.