And on the subject of "literal son of god", anyone claiming that the "vast majority of Christians" have "always believed this" might wish to look at
http://www.vatican.va/archive/ccc_css/archive/catechism/p1s2c2a2.htm - in particular the section that starts 'III THE ONLY SON OF GOD'. I won't quote it, because any out-of-context quote would not adequately summarise the whole, but even scanning it briefly should make it plain and obvious that what is meant by "son" in this context is considerably more complicated than the everyday meaning of the term. As you'd expect, or should expect, for any relationship in which one party is infinite, unknowable, and mysterious