Fantasy/Historical-Fantasy about a Greco-Roman Messiah Figure?

I cannot remember the name of this book. But I rememeber seeing it in the Barnes & Nobles and/or Borders back in the mid to late 2000s. The back cover of the book gave a short summary which was something like . . . " just like the hebrew god sent down their messiah, so too did the Gods of Rome and Greece send a messiah. But he would be a messiah not of peace but of war..." but that is all I remember about the back cover.

I reading the first chapter, and if I remeber correclty it was about the protaganist's mother. I am pretty sure that the book describes her as a prostitute (although I could be wrong). She then becomes mysteriously pregnant but noone is sure who fathered the child. The chapter then shifts to her giving birth and thiese magical events begin to happen. I think the scene is described as having a lot of light emanating from her while she is giving birth. I think, I remember the book describing somekind of monster coming out of her before the human baby. Either way it was something weird. Whatever it was, after this magical delivery the protaganist is born but his mother dies.

That is all I remember of this book. But whenever I try looking it up in Google, I keep getting results like the Da Vinci code which is nowhere close to what the book was.

Anyways, does anyone know what this book is called?

Thanks in advance!