Click here to listen to "From His Heart."

Barack Obama has done more than any recent Democratic presidential candidate to reach out to religious voters, just this week announcing that, as president, he would expand faith-based initiatives and actively encourage religious groups to get more involved in social campaigns. And yet Obama is facing an onslaught of viral attacks questioning his Christian values and accusing him of being a Muslim.

A new Christian political action committee, the Matthew 25 Network, took up Obama's cause with a radio ad released in Colorado Springs, Colo., on Wednesday. Obama was in town that day to discuss patriotism and service to country, but the city is also an evangelical hub, home to Focus on the Family leader James Dobson, a conservative evangelical who has forcefully criticized Obama in recent weeks.

Matthew 25, led by John Kerry's director of religious outreach, Mara Vanderslice, announced in June that it intended to reach out to particular religious communities that it believes Obama must do well with to win in November, including Catholics, moderate evangelicals, Hispanic Catholics and Protestants. This is the group's first ad buy.

The radio spot focuses on Obama's personal faith, rather than on any policy issue. "You know it's an election year when certain people start grabbing headlines by attacking the faith of presidential candidates," a female announcer laments. Acknowledging the rumors surrounding Obama, she continues: "With all these stones being cast at Senator Obama, it can be hard to know what to believe." But the announcer encourages listeners to listen to Obama's personal testimony. "Kneeling beneath that cross on the South Side" of Chicago, "I felt that I heard God's spirit beckoning me," Obama chimes in. "I submitted myself to his will and dedicated myself to discovering his truth." The announcer closes by explaining that the group is sponsoring the ad "because we think it’s time for a better Christian witness in politics."

Salon reports that Christian Broadcasting Network correspondent David Brody found the ad very effective. "I think the ad is extremely strong. It stays away from public policy and really focuses in his personal commitment to Christ. That is a type of message that Evangelicals will want to hear.... You won't find any John McCain radio spots on Christian radio right now," he said.