The roads around the church and probably the first floor of the church itself are flooded.
Even if it were not flooded you’d be asking people to get through floodwaters to get to a place that has no food, no water, and no way out.
You’d create another Astrodome crisis like what happened in 2005.
Why the hell would you want to do that???
Didn’t pictures show it dry?
I would image they have food service capabilities, being a former stadium, but not nearly enough food and no way to get it there from the vendors who may be flooded.