The word ‘Trinity” is not in the Bible. It was a word invented as a label for one of the great mysteries about God. But in several places in the Bible we find that the Father, the Son and the Holy Spirit are spoken of in equal terms.
The word Trinity comes from “tri” = three, and “unity” = one.
Some people say that because they don’t understand the Trinity, God must be misleading us, but the problem is with people, not God. The human brain is very small, and there are some things it cannot comprehend (such as infinite space).
In the case of Jesus, we find that he claimed equality with God. Jesus said many times that he spoke only what the Father spoke, and did only what the Father did. Jesus also performed miracles which only God could perform, and Jesus kept telling people to trust in Him for salvation, when it was the God of the Old Testament who said the same thing about Himself. If Jesus was not equal to God, then he was encouraging idolatry!
One of the clearest demonstrations of the Trinity was when Jesus was baptized. The Father spoke from heaven, and the Holy Spirit appeared in the form of a dove.
The Bible says : “Go … and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Hoty Ghost”.Matthew 28:19 (King James version)