The term Trinity is not used in the Bible, but is the term a person will often hear when discussing the Godhead. However, both terms refer to the same thing which states that God exists in three distinct persons but is still one God.
God in His infinite wisdom gave us an example of the Godhead that we can all understand: time.
Time exists as the past, the present, and the future. The past is distinct from the present which is distinct from the future. God is the Father, God is the Son, and God is the Holy Spirit. Distinct yet one.
The term Godhead is found in three verses: Acts 17:29, Romans 1:20, and Colossians 2:9.
Please remember that even though this term is found three times in the Bible, the teaching is found woven throughout the Word of God. Understanding the Godhead, or Trinity, is essential to understanding the deity of Christ. Jesus Christ was not a man that taught us good moral values - He was God in human form. The Apostle Paul stated in Philippians 2:6-8 that Christ "...being in the form of God, thought it not robbery to be equal with God: But made Himself of no reputation, and took upon Him the form of a servant, and was made in the likeness of men: And being found in fashion as a man, He humbled himself, and became obedient unto death, even the death of the cross".
"In the beginning God created the heaven and the earth." - Genesis 1:1
The very first verse in the Bible tells us that God made everything. Genesis 1:2 tells us that the Holy Spirit moved upon the waters. Was Christ present in creation?
"In the beginning was the Word, and the Word was with God, and the Word was God. The same was in the beginning with God. All things were made by Him; and without Him was not any thing made that was made... And the Word was made flesh, and dwelt among us, (and we beheld His glory, the glory as of the only begotten of the Father,) full of grace and truth." - John 1:1-3, 14
Furthermore, the Apostle Paul wrote "For by Him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they be thrones, or dominions, or principalities, or powers: all things were created by Him, and for Him" (Col. 1:16).
The Apostle John, in a separate letter, also testified to the Godhead when he wrote "For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one" (1 Jn. 5:7).
The Bible tells us that "... at the mouth of two witnesses, or at the mouth of three witnesses, shall the matter be established" (Deut. 19:15, 2 Cor. 13:1). We can see that the Apostle John and the Apostle Paul both testified to the Godhead. Jesus Christ also testified to this truth in the Gospel of John when He said "I and my Father are one" (10:30).
If Jesus and the Father are not one, then there is a contradiction on who is our savior. The prophet Isaiah wrote "I, even I, am the Lord; and beside me there is no saviour" (43:11), and yet, Luke wrote in his gospel "For unto you is born this day in the city of David a Saviour, which is Christ the Lord" (2:11). Notice that not only are both called Saviour, but also, Lord.
God Himself stated that only He is Lord and only He is God (Is. 45:5). God also stated that He will not share His glory (Is. 42:8), and yet, Philippians 2:10 says "that at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth". Additionally, it is Jesus Christ that receives glory (Col. 1:27 and 28, Phil. 4:19).
Not only must the deity of Christ be firmly established in every Christian's faith, but also the deity of the Holy Spirit.
Earlier we noted that the Apostle John testified to God being the Father, the Son, and the Holy Spirit in 1 John 5:7. The Apostle Peter also testified to the deity of the Holy Spirit in the book of Acts.
"But Peter said, Ananias, why hath Satan filled thine heart to lie to the Holy Ghost, and to keep back part of the price of the land? Whiles it remained, was it not thine own? and after it was sold, was it not in thine own power? why hast thou conceived this thing in thine heart? thou hast not lied unto men, but unto God." - Acts 5:3,4
In his letter to the Corinthian church, the Apostle Paul described the gifts of the Holy Spirit that are given to believers. He stated that it is the same Spirit and Lord and God that is responsible for these gifts.
"Now there are diversities of gifts, but the same Spirit. And there are differences of administrations, but the same Lord. And there are diversities of operations, but it is the same God which worketh all in all. But the manifestation of the Spirit is given to every man to profit withal." - 1 Corinthians 12:4-7
By the testimony of God, the Apostle John, the Apostle Paul, and the Apostle Peter we can see that the Godhead is a doctrine that every Christian needs to understand in order to combat false teachings that contradict the Word of God.