I don't want to be on the middle of this but I just want to clarify the concept of trinity:
The word "trinity" did not came from Jesus. You search the Bible and you will never encounter that word. That's why the other "christian" sects that deny this belief use this argument to prove that the Trinity was a mere invention of the Catholic Church.
A little history will enable us to understand why this word "Trinity" had come in. It was the key word that settled a problem caused by the Bible.
Early christians accepted the existence of the Father, the Son, and the Holy Spirit (as what we can found in "our" scriptures) But since they had no time to study the relationship among the divine persons due to persecutions (they had to flee constantly), there was no problem for years. But when Constantine issued the edict of Milan that gave Christians the freedom to practice their faith in 313 AD, it had give them more time to study the Gospels. The first thing that intrigued them was the relationship among the divine persons. How can the existence of these 3 be reconciled with the belief of one God? Since that time, there was no declaration about this, the bishops reflected. One of them was Archbishop Arius of Constantinople. He claimed that Jesus was an "inferior God". This started the controversy that ended in the council of Nicea, where the bishops gather, with the blessing of the Pope, proclaimed that the Father, Son and Holy Spirit are equal: One God in three (but not separated) divine persons, and where the word "trinity" was officially used to describe the Christian God.