I just learned the other day that the Visigoths and most Germans who originally converted to Christianity converted as Arians which means they didn't believe in the holy trinity. They believed Jesus came from God but wasn't God.
Truthfully, this is what I've always believed about Christianity also but I never knew the term was Arian or that it was a fairly popular belief until the Catholic Church forced everyone to convert to the Holy Trinity belief system.
The first century Christians believed that Christ and the Father were distinct beings and that they were both eternal.