The trinity is a doctrine from the devil, therefore it is NOT in the bible!
The terms Father, Son, and Holy Ghost cannot imply three separate persons, personalities, wills, or beings. They can only denote different aspects or roles of one Spirit-being - the one God. They describe God's relationships to man, not persons in a Godhead. We use Father to emphasize God's roles as Creator, Father of spirits, Father of the born-again believers, and Father of the humanity of Jesus Christ. We use Son to mean both the humanity of Jesus Christ and God as He manifested Himself in the flesh for the purpose of man's salvation. We use Holy Ghost to emphasize God's active power in the world and among men, particularly His work in regeneration.
"Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost" (Matthew 28:19).
In this passage, Jesus commanded His disciples to baptize "in the name of the Father, and of the Son, and of the Holy Ghost." However, this verse of Scripture does not teach that Father, Son, and Holy Ghost are three separate persons. Rather, it teaches the titles of Father, Son, and Holy Ghost identify one name and therefore one being. The verse expressly says "in the name," not "in the names."
Father, Son, and Holy Ghost all describe the one God, so the phrase in Matthew 28:19 simply describes the one name of the one God. The Old Testament promised that there would come a time when Jehovah would have one name and that this one name would be made known (Zechariah 14:9; Isaiah 52:6). We know that the one name of Matthew 28:19 is Jesus, for Jesus is the name of the Father (John 5:43; Hebrews 1:4), the Son (Matthew 1:21), and the Holy Ghost (John 14:26). The New Testament church understood this to be so, for they baptized in the name of Jesus Christ (Acts 2:38; 8:16; 10:48; 19:5; I Corinthians 1:13). Matthew himself endorsed this interpretation by standing with Peter and the other apostles during the sermon in which Peter commanded the people to be baptized in the name of Jesus Christ (Acts 2:14-38).
Matthew 28:19 does not teach three persons in one God, but rather it gives three titles of God, all of which properly apply to Jesus Christ. These titles sum up different roles of God; by its singular reference to "name," it focuses upon the one name of God revealed in the New Testament. That name is Jesus.
Further light on this interpretation that the name of God is Jesus comes from a comparison of Revelation 14:1 with 22:3-4. There is one name for the Father, God, and the Lamb. The Lamb is Jesus, so Jesus is the name of God and the Father.