I know that I don't have the credentials to be talking about the Holy Trinity but have you ever had an encounter with an anti-trinitarian? Who are really binitarians because they do believe that the Holy Spirit is fully God and a distinct person they just don't believe that Christ was God "manifest in the flesh" (1 Timothy 3:16)? Well I recently had an encounter with a United Pentecostal on the topic of the Trinity and it's not a pretty site to watch their face snarl and nostrils flare as their voice gets louder and louder after you have pointed out that Jesus Christ was not just the Son of God but also God the Son and that all major cults on the face of the earth also deny the deity of Christ, and that only historical Christianity confirms the Trinity as God the Farther, God the Son and God the Holy Spirit, three distinct persons being fully God, yet one God. Can I explain how this can be? Of course not, I am only a feeble minded creature trying to ponder an infinite Creator that has been divinely revealed to us in Scripture. But just because I can't explain it does not mean that I should over look the overwhelming evidence presented to me from the Bible and deny the doctrine of the Trinity just because it doesn't make sense to me. The doctrine of the Trinity was progressively and clearly revealed throughout scripture but rather than trying to give you an exhaustive list of verse's to prove my point here are just a few thoughts to ponder and some audio resources to help you along.
First it's quite clear that Isaiah thought the Messiah would be "The mighty God". Isaiah 9:6 "For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counsellor, The mighty God, The everlasting Father, The Prince of Peace."
The apostle John sure thought that Christ was God, John 1:1 "In the beginning was the Word, and the Word was with God, and the Word was God." and then in John 1:14 "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 also confirms his statement of the Word being manifest in 1 John 1:1-2 "That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, of the Word of life; For the life was manifested, and we have seen it, and bear witness, and shew unto you that eternal life, which was with the Father, and was manifested unto us;"
The apostle Thomas called Jesus God and then Jesus approved of his statement in John 20:27-29 "Then he said to Thomas, "Put your finger here; see my hands. Reach out your hand and put it into my side. Stop doubting and believe." Thomas said to him, "My Lord and my God!" Then Jesus told him, "Because you have seen me, you have believed; blessed are those who have not seen and yet have believed."
I have already pointed out that the apostle Paul believed that Christ was God in the flesh 1 Timothy 3:16 "And without controversy great is the mystery of godliness: God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory."
Scripture is so clear as to the deity of Christ that to deny this truth one must be blinded by the adversary to deny such claims of the Bible. If you are struggling with this doctrine I highly recommend downloading Wayne Grudem's very insightful four part audio study on the Trinity available for free download at monergism.com