Many books have been written about the subject of the trinity, so I can only give the briefest of summaries. One of the problems we have in understanding the trinity is that in this doctrine we are trying to define and understand the basic makeup of God. We do not have adaquate mental or spiritual powers to fully grasp who God is or what He is like. Men trying to understand God would be something like trying to explain to an ant what human life is like. There is just not enough things in common to begin with.
However, God does tell us about Himself and we should try to understand as much as we can. The doctrine of the trinity comes from bringing together two other doctrines that at first seem opposites to each other. Here they are:
- The Bible clearly teaches that there is one God and only one God. Deuteronomy 6:4 states, "Hear, O Israel: The LORD our God is one LORD." This is only one of many verses which teach this truth.
- Yet, the Bible also clearly teaches that there are three persons who are called God: the Father, the Son, and the Holy Spirit (or Holy Ghost). Though it would take too much space here to establish these truths, they are clearly taught in the Bible.
This brings us to the question of how this could be. How can there be one God and three Gods? Well, the Bible never says there are three Gods. There is only one God. Yet, each of these three persons are God. We must realize that God has an essential structure that transcends our earthly experience. But we must reach for the closest we can come to an understanding. The conclusion Bible students through the ages have come to is that there is only one God, but there are three persons in that Godhead. This is the trinity, or the three-in-one God. 1 John 5:7 states, "For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one." This is an excellent summary of the trinity in one verse. However, we can see this connection in other verses as well.
Matthew 28:19 - "Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost." Notice, there is one name with three persons sharing that name and authority.
2 Corinthians 13:14 - "The grace of the Lord Jesus Christ, and the love of God, and the communion of the Holy Ghost, be with you all. Amen."
For the sake of time and space, I must close here. However, I hope this gives you a beginning from which you can grow in your understanding.