Oscar Isaac as Joseph in The Nativity Story.

What did the cast do to get in touch with how life was lived 2,000 years ago?

We had a month-long Nativity camp. There is a place called Nazareth Village [that] I thought could be some cheesy tourist trap, but they're recreating the Nazareth Village with the same materials and stones and tools as they're excavating it. One guy trained Oscar Isaac-who plays Joseph-how to build with the stonework and the carpentry with those same tools. So Oscar built one wall of his house that you see in the movie and really got blisters on his hand. Then Keisha learned how to milk the goats, to grind the flour, to weave the cloth from the goats and the sheep's wool. It was good because we just did that every day for like a month. Suddenly, it just becomes natural. I feel like I got a like a couple of master's degrees on this, or at least maybe an associate degree from a community college.

Keisha is not of Middle-Eastern descent. Was this something you thought about during the casting process?

Yes. I had the naïve idea that we would go casting in Tel Aviv and find the perfect Israeli girl. That just doesn't really add up. Somebody like Keisha with her depth and intuition and soul-what she can bring to this movie-obviously does not come around in every town. There's a reason why she's the youngest girl to ever be nominated for an Academy Award for best actress. But we looked. We had casting directors in Rome, Tel Aviv, Paris, London, New York, and L.A. — and one in Morocco, and some people in Syria looking all over. Really, there wasn't even a second choice after Keisha. But we have several Israeli actors; we have people from Jordan. We have cast members from 23 countries, and we tried our hardest to be as authentic as we could. I joked [that] there were almost no white people used in making this movie that we did. But there's a couple that snuck in. There's two Irish actors, actually, that I think fit into our Middle Eastern world.

What was it like shooting the actual birth scene?

Being there, it felt very gritty. We had all the real animals right there in the cave, in the grotto with us. They didn't care about the filmmaking process. You had the real hay. We were outdoors filming it. We tried to really imagine [what it would be like] if you were this guy, and you had promised this girl's parents that you were going to take care of her, then she suddenly went into labor right outside this little town of Bethlehem. There's no bed. There's no nothing. And you end up out of desperation laying her down in this stable. It's pretty intense. And she's a young girl in extreme pain.

In the manger in The Nativity Story.

In the story, how do you address the idea of the Immaculate Conception? Is that played as if Mary's telling the truth about being a virgin?

You see an angel in the movie, [and] she believes it. So if you wanted to give it a secular spin, a non-religious spin, you could say this movie is kind of like magic realism, like some of the beautiful Latin American films and novels. There is that magic realism quality, but we interpret it the way that Matthew and Luke interpreted it in the Bible.

And probably a lot of people are going to ask you about Keisha being pregnant. What do you think about that?

We were all a little bit surprised to say the least when we heard the news. I think the amazing thing is that she thought long and hard, but she ultimately came to the decision that she wanted to have the baby and bring that baby up in a loving, wonderful environment. So I really respect a courageous decision like that and I think as just even more testament probably to her strength and her courage. She and her mom were here a week or so ago. Because her mom just had a baby too, they'll be two babies growing up in that house together. It'll be pretty fun. One will call the other one uncle even though they're only like 6 months apart. But her mom is very loving and then she's got five kids already, so it's a very fun, artistic, creative household with paintbrushes and easels all around. I am sure it will probably be a really incredible kid.

How do you think this fits in with the larger trend of the religious filmmaking, especially with The Passion of the Christ?

I'm sure it'll never be as seismic as that because that had all its attendant controversy and the Mel controversy and anti-Semitism and everything. And it [was] a very powerful dramatic story, rated R with all the violence and the blood. This is really quite different than that, because it's more about love and faith and tolerance. And it's a very beautiful story. I hope that it's inspiring on a lot of levels.