Criticism of Mr. Osteen intensified after the church, which holds services in a 16,000-seat arena that used to house the Houston Rockets basketball team, posted on Facebook on Sunday that the building was inaccessible because of “severe flooding.”

“We want to help make sure you are safe,” the post said, before providing a list of shelters in the area.

Those two messages tipped off a days-long backlash as social media users questioned why the church was not doing more to help those affected by a storm that has left tens of thousands seeking shelter from rising floodwaters. Many others rushed to the defense of the church, which is home to one of the nation’s largest congregations.

“If you guys at Lakewood cared half as much about your own people as you do your Sunday offerings, you’d definitely have those doors open,” said a Facebook user, Gary D. Coleman, in a comment that was representative of hundreds of others that were left on the post.

“You all do realize that it takes a significant staff to open the doors and keep a church running as a shelter?” said another Facebook commenter, Laurie Marie Campbell. “It could very well be that pastor Osteen’s staff can’t get there, because the roads are flooded.”

At about 11 a.m. Tuesday, Mr. Osteen announced that the church was available to anyone seeking shelter. He said that he and his co-pastor and wife, Victoria Osteen, “care deeply about our fellow Houstonians.”

The church had said on its official Twitter account earlier in the day that it was receiving those who needed shelter, and added that it was collecting diapers, baby food, formula and other supplies.