Hi, there -
I believe the trinity is plainly described in scripture even though the word "Trinity" is never specifically used. The word "Rapture" is never used either, but most Christians believe it will happen just the same.
The best example of the trinity being described is the telling of the baptism of Jesus. Here you have the Son being baptized, the Father speaking from heaven, and the Holy Spirit descending in the form of a dove.
I believe that God is both one and three, just as we who were created in His image are one person with three distinct parts, body, soul, and spirit. I believe the three members of the Trinity are distinct individuals who make up the God-head and function with one mind and purpose.
I also believe that if you disagree, we'll find out when we get to heaven.

Because I DON'T believe it's worth fighting about.
Gene.