Trinity is a word that is not mentioned in Scripture one time.
A Father and Son can be "one" in values, intent, purpose, and vision,
they can share many things,
but they are not one being or interchangeable beings.  
John 3:16 tells us the Son of G-d was begotten.  
G-d Himself is eternal or unbegotten.
And Y'hshuwah, when he was
baptized, went up straightway
out of the water:
and, lo,
the  heavens were opened unto him,    
and he saw the Spirit of G-d
descending like a dove,
and lighting upon him:
And lo   a voice from heaven, saying,
This is my beloved Son,
in whom I am well pleased.
     Matthew 3:16,17