There was no defining moment in the war that made Peter Moeller walk away from his Lutheran upbringing and question the existence of God.
His faith eroded gradually over the eight months he served as a medic in Iraq with the Iowa Army National Guard's 109th Medical Battalion.
"I began to think a little too deep, and it ruined that whole belief for me," said Moeller, 24, now of Cedar Rapids. "... I believe in the possibility there may be a God, but that whole organized religion thing went right out the window really fast."
He said he kept stumbling over one point.
"I'm a Christian fighting in this war, and there's a Muslim fighting against me. We both think we're right," he said. "Who's to say they're not the right one? Who's to say we're not wrong?"
For many soldiers, serving in a war zone can have a dramatic effect on faith. Like Moeller, some may be left with more questions than answers. Others turn to God in thanks or to seek comfort as they mourn fallen comrades.
"From a faith perspective, the challenge for all who serve is that at any point you're in a life-or-death situation, and when you're constantly facing death, you're questioning your perception of eternity," said Murray Phillips, who serves as a chaplain for the 67th Troop Command in Iowa City. He served in Afghanistan in 2003.
"Those soldiers who had a strong faith in Jesus Christ, their faith was very much strengthened over there," Phillips, 44, said. "If they were at a point where they were faltering before (going to war), they could have fallen even more."
Pete Martin, 56, served a year in Iraq with the 425th Transportation Company based in Sioux City. While he had faith growing up, it became a significant part of his life when he joined St. Andrew Lutheran Church in Cedar Rapids five years ago.
Before his departure for Iraq in 2005, his faith especially grew. "The closer I got to getting on that plane, the more I started thinking about my own mortality and my faith," Martin said.
With his dog tags, he wears a tag that carries a passage from Joshua 1:9: "Be strong and courageous." In Iraq, he said, "my faith gave me a lot of strength. I felt stronger knowing that God was with us, that he was keeping us from losing any of our unit."
For Moeller, however, war provided a different picture. As a medic, he was facing death and serious injuries daily. He questioned himself often.
"It's a tough time to break away. There's a lot of intense thinking," he said. "It wasn't like I woke up one day and said, 'OK, I don't believe in religion anymore.'"