Huckabee - who raised his hand at a debate last May when asked which candidates disbelieved the theory of evolution - asked this time why there is such a fascination with his beliefs.
"I believe God created the heavens and the Earth," he said at a news conference with Iowa pastors who murmured, "Amen."
"I wasn't there when he did it, so how he did it, I don't know," Huckabee said.
But he expressed frustration that he is asked about it so often, arguing with the questioner that it ultimately doesn't matter what his personal views are.
"That's an irrelevant question to ask me - I'm happy to answer what I believe, but what I believe is not what's going to be taught in 50 different states," Huckabee said. "Education is a state function. The more state it is, and the less federal it is, the better off we are."
The former Arkansas governor pointed out he has advocated for broad public school course lists that include the creative arts and math and science. Why, then, he asked, is evolution such a fascination?
In fact, religion seems to be more of an issue in the GOP Iowa caucuses with one month left before the voting.
In recent weeks, Huckabee has moved from the back of the pack in the state to challenge longtime leader, who would be the first Mormon president. The race is now a dead heat, with the Iowa caucuses - the first contest in the nomination fight - set for Jan. 3. Christian evangelicals, by many estimates, make up anywhere from 30 percent to 50 percent of Republicans who will attend the caucuses.
Huckabee, at a dinner in Des Moines, told reporters that the theory of intelligent design, whose proponents believe an intelligent cause is the best way to explain some complex and orderly features of the universe, should be taught in schools as one of many viewpoints. "I don't think schools ought to indoctrinate kids to believe one thing or another," he said.
Earlier Tuesday in Newton, Iowa, Huckabee wouldn't say whether he thought Mormonism - rival Romney's religion - was a cult.
"I'm just not going to go off into evaluating other people's doctrines and faiths. I think that is absolutely not a role for a president," the former Arkansas governor said.
While he said he respects "anybody who practices his faith," Huckabee said that what other people believe - he named Republican rivals Romney,, and Democrat - "is theirs to explain, not mine, and I'm not going to."
As he has risen in polls, Huckabee has emphasized his own faith and in recent weeks has sought to draw subtle distinctions with his rivals by running a TV ad on the issue in the state.
"Faith doesn't just influence me. It really defines me. I don't have to wake up every day wondering what do I need to believe," Huckabee says in the ad. "Let us never sacrifice our principles for anybody's politics. Not now, not ever."