One God in Three Persons
Christians believe in the Trinity because there is only one God. “Hear, O Israel; the Lord our God is one Lord.” Deuteronomy 6:4. “Before Me there was no god formed, neither shall there be after Me.” Isaiah 44:6
Because the Bible clearly teaches that the Father is God, that the Son is God and that the Holy Spirit is God, Christians are compelled to accept that God is eternally existent in three Persons. The Christian doctrine of the Trinity states that there is only one God, eternally existent in three Persons.