Looking for a Non-Christian, Non-Divine Retelling of the story of Christ

For a while now, I've been curious about and searching for the existence of a "serious" (not a farce or comedy) retelling of the story of Jesus, one that takes his miracles and provides a, shall we say, non-divine explanation for the stories we see in the Bible today. I want a piece of fiction, not a scholarly work or critique of the Bible. Bonus points if the book is well researched and paints a realistic picture of the world in which he would have lived.

I'm not looking for something that shits all over religion, but a good-faith (lol) effort to "explain" via plausible scenarios the life of Jesus of Nazareth, the man, the carpenter, the human.

I thought the concept interesting, and have yet to find a book that scratches this itch. Surely one must exist?