One God as Trinity is the Father, Son, and Holy Spirit. While the Bible never uses the word Trinity, it clearly reveals one God in three Persons. The triune God works in perfect harmony from the beginning to the completion of our eternal salvation. There is election by God the Father, redemption by God the Son, and regeneration by God the Holy Spirit.
Consider this illustration of one God as Trinity. You may draw a triangle on paper to illustrate the Trinity. It is one triangle with three distinct points. So, there is one God in three distinct persons as Father, Son, and Holy Spirit.
Believers encounter one God as Trinity through prayer. We pray to God our Father, in the name of God the Son, through the presence and power of God the Holy Spirit. Jesus teaches us to ask the Father in His name (John 14:13). Scripture teaches us to pray in the Spirit (Ephesians 6:18; Jude 20).
The testimony of one God as Trinity is baptism. It's a public testimony to one God in Trinity. Jesus commanded us to baptize believers in the name of the Father, Son, and Holy Spirit (Matthew 28:19). Notice that baptism is not in the names plural, but the name singular. It's in the name of God as Father, Son and Holy Spirit.
