Summary: The Bible does not spell out “Trinity.” The idea of the Trinity is so ingrained in Christianity that it is nowhere described, but assumed in Scripture. Our text, for example, presents the Trinity as a fact, without explanation.
This is a core doctrine which no one can deny and still be called “Christian.” It’s not something that must be understood to be saved; rather, it is something that cannot be denied in full knowledge.
Examples Fail to Explain the Trinity!
Legend says St. Patrick used clover leaves to teach the Trinity. But clover is inadequate due to the nature of clover: some clovers have four leaves.
The illustration of the Trinity as an egg also fails; shell, yolk, and albumen, because the parts do not share their attributes among them.
The three states of water (liquid, steam, and ice) fails for the same reason. These three never appear together in nature.
All of these lead to a heresy called "Modalism," which the early church refuted: i.e. God shows up in a form that best suits the situation at that time; sometimes the Father as in the OT, sometimes the Son as in the Gospels, usually now as the Holy Spirit from the Book of Acts until now. (e,g, Oneness Pentecostalism, or the popular book The Shack).
What about “The Johannine Comma” in 1 John 5:7-8?
This passage is one of the few in the KJV that are “too good to be true.” We must be honest about what our Bibles do and do not say. The doctrine of the Trinity does not rise or fall on this one passage.
It’s a 9th century Latin Vulgate corruption that entered the Greek manuscript tradition in less than 6 copies. The first Greek manuscript that has the “comma” dates from the 15th century. It is absent from the early Ethiopiac, Aramaic, Syriac, Slavic, Armenian, Georgian, and Arabic translations.
The Persons of the Trinity Share Attributes
Each Person of the Trinity is Eternal, Creator, Omnipresent, Omniscient, Omnipotent, has a will. Each acts alone and together, gives life and strength to believers. They appear together in many places in the Bible: Genesis 18; Matthew 3:16-17, 28:19; Luke 3:22 just to mention a few.
Most denials of the Trinity are attacks on Jesus’ Divinity
Mormons, Jehovah’s Witness’, Islam, Scientology, and Christian Science all deny the Deity of Jesus, and modify His humanity to fit their theology. By denying the Deity of Jesus they over emphasize his humanity. The opposite mistake is just as bad, to over emphasize his Deity to the exclusion of his humanity.
The mystery of the Hypostatic Union is also at stake: Jesus was both 100% human and 100% God. If Jesus was not fully both, he could not be both our Lord and our Savior. If Jesus were only Divine, he could be our God, but not our Savior, Jesus could never have died for our sin. As God, Jesus could never have been the Suffering Servant of Isaiah 53, or the dying Messiah of Psalm 22. If Jesus were merely human, he could be our example of a good man, as in his baptism, but could not be our Savior, Jesus could not have been raised from the dead if he were only a man.
What you believe about Jesus, what you believe about the Trinity affects who you are in Christ..