They're spreading the word of God, one church at a time.
On Sunday, the Buffalo Mass Mob took over the Holy Cross Parish on Buffalo's west side.
The Mass Mob, which is in its third year, travels to different historic churches in Buffalo. The goal is to increase enrollment in the Catholic Church and discover Buffalo's oldest houses of worship.
The Mass Mob travels to churches every two months to bring attention to the churches.
People who attend the masses also increase offerings for that church.
About 500 people were in attendance on Sunday.