For the Rev. David Uth, the head pastor of First Baptist Orlando, there was no mistaking the evolution of his traditionally white congregation, as he discovered in recent years that immigrants speaking at least 32 different languages had flocked to his doors. Mr. Uth is one of the pastors going to Washington this week.

His church offers ministry in seven foreign languages, with simultaneous translation of Sunday services in Spanish and Portuguese and a separate Brazilian service on Sunday evenings.

“The stories out there in the pews are stories of people from all over the world who have made friends and who have become close with people here,” Mr. Uth said after his service last Sunday. “I think that’s why there’s movement in this church, there’s momentum, there’s an openness to try to do something to address their needs.”

Mr. Crenshaw said his views started to shift when his Colombian friend, a white-collar professional who had been living in Florida for years, asked for help after being arrested for driving without a license. Mr. Crenshaw said he realized that his friend, an active church member who was supporting his mother and a brother, could be deported because of the traffic offense.