"Jesus Christ, the Son of God" - Mark 1:1 (50-80 CE, that is 20-30 years after Christ's death)
"There is only one physician - of flesh yet spiritual, born yet uncreated, God incarnate, genuine life in the midst of death, sprung from Mary as well as from God, passable yet impassable - Jesus Christ our Lord" (7:2) - St. Ignatius letter to the Ephesians (ca. 107 CE)
"Constantine needed to strengthen the new Christian tradition, and held a famous ecumenical gathering known as the Council of Nicaea (325 CE)...many aspects of Christianity were debated and voted upon - the date of Easter...the administration of sacraments, and of course, the divinity of Jesus... until that moment in history, Jesus was viewwed by His followers as a mortal prophet...Jesus' establishment as 'the Son of God' was officially proposed and voted on by the Council of Nicaea.... Constantine commissioned and financed a new Bible, which omitted those gospels that spoke of Christ's human traits" - Dan Brown, "The Da Vinci Code" p. 233-234 (ca. 2003 CE)
I just read that in the Da Vinci code the other day and had to laugh. I know there's about a hundred websites that attack the book but I figured I'd take 10 minutes and prove that the Deity of Christ was an idea LONG before Nicea. Congratulations Dan Brown, you read the wikipedia entry on Arianism and found out some people didn't believe in the co-eternality of Christ with the Father...but you didn't read the part where it said many Arians believed Jesus was a demi-god or God but created....
At least Marcus Borg and Dominic Crossan have a working thesis "Son of God" is a secret joke misunderstood by the Church for 2000 years. That is plausible, though unlikely. The only respectable way you can debate the historical account of Christianity which include all those troublesome Church Father references to his divinity is if you claim that all of the history is unreliable....which some have tried.
So take it or leave it, as C.S. Lewis once said:
“I am trying here to prevent anyone saying the really foolish thing that people often say about Him: “I’m ready to accept Jesus as a great moral teacher, but I don’t accept His claim to be God.” That is the one thing we must not say. A man who said the sort of things Jesus said would not be a great moral teacher. He would either be a lunatic — on a level with the man who says he is a poached egg — or else he would be the Devil of Hell. You must make your choice. Either this man was, and is, the Son of God: or else a madman or something worse. You can shut Him up for a fool, you can spit at Him and kill Him as a demon; or you can fall at His feet and call Him Lord and God. But let us not come with any patronizing nonsense about His being a great human teacher. He has not left that open to us. He did not intend to.”