NASHVILLE, Tenn. — The nation’s largest Protestant denomination continues to see a decline in membership.

Statistics released Tuesday by the Southern Baptist Convention’s Lifeway Christian Resources show membership in 2011 decreased by .98 percent to just under 16 million. That marks the fifth straight year of decline.

The number of churches increased slightly, but the total number of congregations dropped as the denomination lost several church-type missions. These are smaller congregations that are supported by larger churches.

The number of baptisms increased slightly last year — an important measure for a denomination with an expressed mission to win souls for Christ. But Lifeway Research President Ed Stetzer downplayed the significance of that gain of less than 1 percent.

“Baptisms had their second lowest year in the last 50 years, so this is not a time to pull out the party hats,” he said.

Stetzer said the overall trend is that baptisms and membership are declining for the Nashville-based denomination. And for membership that decline is accelerating.

Those changes mirror the declines that mainline Protestant denominations such as the Methodists have been seeing for decades.

Duke Divinity School Professor Curtis Freeman, who directs the Baptist House of Studies, said the Southern Baptists had resisted the trend, in part because of their commitment to evangelization.

“I think that, in some ways, they are every bit as passionate about evangelism as they’ve always been,” Freeman said. “It’s just that culturally the tide is going a different way. … It’s increasingly becoming a secular culture, not a Christian culture.”

Stetzer agreed that the culture is changing, but said that was no excuse for decline. He noted that some denominations, such as the Assemblies of God, are still finding a way to grow. Southern Baptists can do that too, he said, but not if they continue to operate as they always have.

“Denominations don’t change until the pain of staying the same grows greater than the pain of changing,” he said.

The statistics were released on Tuesday, a week ahead of the denomination’s annual meeting.