WASHINGTON (AP) — Presidential contenders Barack Obama and John McCain, trying to woo conservative Christians during a religious forum Saturday, differed on abortion, with McCain saying a baby's human rights begin "at conception," while Obama restated his support for legalized abortion.

The candidates, appearing on the same stage for the first time in months, although they overlapped only briefly, shared their views on a range of moral, foreign and domestic issues during the event at Saddleback Church in California.

The forum, during which Saddleback's influential pastor Rick Warren asked each candidate questions for an hour — the two men briefly shook hands and hugged each other during the switch — was an opportunity for each to court an influential voting.

Religious conservatives have largely supported the Republican Party, and many of McCain's positions are more in line with conservative Christians, who comprise about one-quarter of the U.S. electorate, and who helped push President George W. Bush into office.

When asked about abortion, a key issue for many conservative Christians, McCain expressed his anti-abortion stand simply and quickly, saying human rights begin the instant that a human egg is fertilized. McCain, who adopted a daughter from Bangladesh, also called for making adoption easier.

Obama, who supports legalized abortion, said he would limit abortions in the late stages of pregnancy if there are exceptions for the mother's health. He said he knew that people who consider themselves pro-life will find his stance "inadequate."

He said the government should do more to prevent unwanted pregnancies and to help women who give birth, such as provide needed resources to the poor, as well as better adoption services.

On another contentious issue — gay marriage — both men said marriage is a union between a man and a woman. Obama added that he supports civil unions for gay partners, giving them rights such as hospital visits with one another.

He said he opposed a constitutional ban on gay marriage, calling the matter a state issue.

McCain's answer was less clear. If a federal court ordered his state, Arizona, to honor gay marriages allowed in Massachusetts, he said, "then I would favor a constitutional amendment. Until then, I believe the states should make the decisions within their own states."

Warren is best known for building Saddleback in Lake Forest, California into a 23,000-member megachurch, and for writing the multimillion-selling book "The Purpose-Driven Life," about helping people find meaning and purpose in life.

The forum offered Obama, who would be the U.S.' first black presidenti, a chance to show his comfort talking about his Christian faith and to rebut rumors that he is a Muslim. A recent poll by the Pew Research Center for the People and the Press found that 12 percent of respondents believe the Democrat is Muslim.

The son of a Kenyan father, Obama has the middle name Hussein and lived in the largely Muslim nation of Indonesia as a child.

In several cases, the Illinois senator gave a Christian interpretation to his generally liberal political views. He said he is redeemed by Jesus, who died for his sins.

The Obama campaign has been diligently courting religious voters with a presence on Christian radio and blogs, and through "American Values Forums" and other events.

While many of the McCain's views, including opposition to abortion, match the outlook of conservative Christians, he is far less comfortable than Obama talking about religion. He did not participate in a spring forum at Messiah College near Harrisburg, Pennsylvania, where Obama and New York Sen. Hillary Rodham Clinton, who later ended her quest for the Democratic presidential nomination, discussed religion and their personal lives.

During the Saturday forum, McCain tended to give shorter, less complex answers, winning somewhat more applause than Obama from the large, evangelical church's audience.

Supporters of McCain have taken to circulating excerpts from his memoir "Faith of Our Fathers," that explain his beliefs. He recently met privately with Roman Catholic Archbishop Charles Chaput of Denver, one of the most vocal U.S. bishops on the duty of Catholics to make the abortion issue a priority in choosing public leaders.

When asked about America's greatest moral failure, Obama said it is the insufficient help the U.S. gives the disadvantaged. He noted that the Bible quotes Jesus as saying "whatever you do for the least of my brothers, you do for me." He said the maxim should apply to victims of poverty, sexism and racism.

McCain said the nation's greatest moral shortcoming is its failure to "devote ourselves to causes greater than our self-interests."

After the September 2001 terrorist attacks, McCain said, there should have been a national push for joining the Peace Corps and other volunteer organizations. His comment seemed an indirect criticism of Bush, who had urged tax cuts and more shopping to stimulate the economy at the time.

McCain also said he would pursue Osama bin Laden "to the gates of Hell," another goal that might be seen as a swipe at Bush's administration, which has failed to capture the architect of the Sept. 11 attacks.

McCain, asked the toughest decision in his life, cited his refusal to be released ahead of fellow U.S. prisoners of war in North Vietnam. "It took a lot of prayer," he said. The Arizona Republican has tried to portray himself as the more experienced candidate, able to handle national security and foreign policy issues more adeptly than his Democratic counterpart, in part due to his military experience.

Meanwhile, Obama's campaign announced that it raised more than $51 million in July and the Democratic National Committee reported $27.7 million in donations last month. His July total was slightly less than the $52 million he raised in June.

Obama's Internet-powered fundraising efforts have shattered all previous records for a presidential campaign, bringing in a total of $390 million so far. The Illinois senator has announced he will forgo public financing for the general election, giving up $84 million in taxpayer money for the final two months of the campaign and committing himself to a steady pace of fundraising.

By contrast, McCain has raised just $140 million and has agreed to accept public financing for the general election and the spending restraints that come with it. McCain has remained competitive, however, because of the fundraising success of the Republican National Committee.

McCain's campaign said Friday he had raised $27 million in July, his biggest monthly haul since clinching the party's nomination. McCain's campaign reported having $21 million available to spend.