I love The Iliad, but I'm not sure I can agree that it's the first great book post-Bible. The Epic of Gilgamesh is also a great book, and definitely predates it.

I'm not a follower of Christ, but the book still stands out as a fantastic work. Like (I suspect) a lot of folks, I was exposed to The Odyssey first (as an assignment in graded school), because it's got a more straightforward "adventure" narrative, but The Iliad is really the masterpiece, a book that juggles so many characters, goals, and concepts and does it beautifully. I was raised on the Fitzgerald translation, but I love the Fagles and Wilson ones as well.