There is One True God eternally existent in 3 distinct Persons: God the Father, God the Son, and God the Holy Spirit. 3 Persons who share the same divine nature (3-in-1; God’s nature).
Deut 6:4, Isa 43:10-11, Matt 28:18-20, Luke 3:22, 1 John 5:7 NKJV