The first family arrived at a chapel at Marine Corps Base Hawaii mid-morning for a multi-denominational service. The Obamas were greeted by about 100 clapping parishioners and a band playing "Joy to the World" as they were led to their seats in the front row.
In his sermon, chaplain Steve Moses asked worshippers to recommit to God in the new year. He also joked that the reason God put him through a heart surgery was so he wouldn't suffer a heart attack while preaching before the president.
Obama was the first worshipper to take communion, dipping the wafer in wine before placing it in his mouth.
Though Obama speaks frequently about his Christian faith, his family rarely attends church services in Washington. The White House says the president hasn't joined a parish because his appearances would be disruptive to the rest of the congregation, though he does attend private services when he spends weekends at Camp David, the presidential retreat.
Obama last attended church in September, shortly after a poll was released indicating that a majority of Americans had doubts about the president's religious beliefs.
During the hourlong service, Obama and the other churchgoers sang along to a youth band playing Christmas carols such as "Silent Night" and "Oh Holy Night."
After church, Obama went golfing on the Marine base despite sporadic light rain.
The president and Mrs. Obama also extended wishes to people celebrating Kwanzaa. "The seven principles of Kwanzaa - unity, self-determination, collective work and responsibility, cooperative economics, purpose, creativity and faith - are some of the very values that make us Americans," the Obamas said in a statement issued by the White House.
Associated Press writer Julie Pace in Honolulu contributed to this report.