Thank you for contacting BibleAsk.
The Bible teaches that God is one in essence, three in Person: the Father, the Son, and the Holy Spirit (Matthew 3:16-17; 28:19). God is not three gods but One. Finite human minds can’t fully understand the nature of God. Like one rope with three united strands, the three persons of the Father, Son, and Spirit make up the One God.
The confusion regarding the number of beings composing the Godhead springs from a simple misunderstanding of the word “one.” “One” in the Bible does not always mean numerical quantity. Depending on the Scripture, “one” can often mean unity.
“Therefore a man shall leave his father and mother and be joined to his wife, and they shall become one flesh” (Genesis 2:24, emphasis added). “One flesh” here does not mean that a married couple melt into one human after their wedding, but rather they are to be united into one family.
Jesus prayed that the apostles would be one, saying, “And the glory which You gave Me I have given them, that they may be one just as We are one: I in them, and You in Me; that they may be made perfect in one” (John 17:22, 23).
In the Holy Bible, God commands, “You shall have no other gods before me” (Exodus 20:3). Being the only true God, the Lord requires that He alone be worshiped.
Jesus affirms that, “…The Lord our God is one Lord.” (Mark 12:29). The Scripture passage here quoted reflects the distinctive belief of the Jews and Christians in the one true God, in contrast with the many gods of the nations.
The New Testament writings are sprinkled with this concept of one God with three united, fully divine persons. “There is one body, and one Spirit, even as ye are called in one hope of your calling; One Lord, one faith, one baptism, One God and Father of all, who is above all, and through all, and in you all” (Ephesians 4:4–6).
In the Godhead the Father and Spirit are invisible while the Son is visible. Man is also a “tri-unity,” having physical, mental, and spiritual components. Again, two are invisible (mental and spiritual) and one visible (physical).
In His service,