amadeusApparently you have the same disease as did Dave L.
Telling @amadeus that he is wrong for denying the Trinity is not going to do him any good. You need to help him believe in the truth by showing him the Trinity from scripture.
People believe what they believe for a reason. Most people are not going to change what they believe simply because they are told that they are wrong. They need to be shown the truth. Give them a reason to believe in the truth, other than the condemnation that you are currently heaping upon them.
Most people will not believe what you tell them because coersion. Even people that have converted to Islam because of the sword have retained their Christian faith as moderates; of course when it comes down to the nitty-gritty, they will confess that Jesus is the Son of God if God abides in Him and He in them, even in the face of the sword of Islam.
But my point being that, if you cannot show from the Bible the reality of the Trinity, nor can show from the Bible the essentiality (concerning salvation) of it as a doctrine; then your condemnation of those who do not hold to that doctrine is only based on your opinion and not the word of the Lord. Therefore there is no need to fear the condemnation that you are preaching about.
But if you can show from scripture that believing in the Trinity is essential for salvation, those who do not believe in it will be forced to at least look at it as a doctrine to see whether the Bible actually teaches it so that it would be absolutely sound doctrine.
Don't get me wrong, I believe in the Trinity myself...I'm just not certain that people who are searching for the truth are necessarily condemned if they don't believe in it yet.
I see the deity of Christ as absolutely essential (John 8:24, Exodus 3:14); but there is no verse or passage in the Bible that I can find that condemns disbelief in the Triune nature of the Lord. While I believe that the Bible teaches this doctrine; and if one is aware of the verses that teach it so clearly, to disregard or deny them would be to deny Christ, who is the Word: if someone is unaware of the verses that teach it and are still developing their theology, the Lord is not going to condemn them for their lack of knowledge (as long as they are seeking accurate knowledge); but He looks at their heart: and if they love Him, they are known by Him (1 Corinthians 8:3).
And I have discussed this number of times before. He has made it clear accepting the Trinity is a nonstarter for him.
Remember, he thinks Bible study is a problem. He thinks he gets all his information straight from the Holy Spirit.