Have you found one verse in the Bible that clearly teaches the trinity?
Have you told us why you think this, or any, doctrine has to be taught in just ONE verse?
A doctrine that important should be clearly taught all over the Bible.
It is.
But I'll be satisfied with just one verse
No you won't. You've been given more than one verse; you don't want to accept them.
You might be happy if there was one verse that used the word Trinity, or if Jesus said; "God is a trinity." Although maybe not. You are trying to argue that the concept and doctrine don't exist because that one particular word is not used.
There is no verse that says that blood transfusions are forbidden, yet JWs - if that is what you are - believe that to be a Scriptural teaching.
OR, if you care to, you could show me one major teaching of the Bible that is NOT clearly taught repeatedly.
Er wait a minute - one minute you want ONE verse to prove the trinity, the next you are saying that major doctrines and truths about God are taught over and over again in the Bible.
God is one; there is only one God, there is no other god but God, no other Saviour but the Lord. He is the first and the last, the Alpha and Omega - eternal God, who was present in the beginning and before the beginning. He alone is God; there is no other.
Yet it is clear from Scripture that God is Father; the word of God, who became flesh, Jesus, is God; and the Spirit is also divine and eternal. Three divine beings - but there is only ONE God.
I can give you all the verses that show what I am saying, if you wish.
As long as you are prepared to genuinely consider them, and not come with a lot of preconceived ideas; determined to shoot them down in flames because that is what you have been taught to do.
The trinity is a Christian doctrine. It is expressed and summed up in the Nicene creed. Many groups and cults which reject the Trinity are not considered mainstream Christian denominations, or part of the Christian church. I am pretty sure a person is not meant to display a Christian icon by their name on this forum, if they don't accept the creed.