This is really great. These massive big box stores have no other purpose than these giant retail spaces, and to see people think outside the box (har har) and put them to a legitimately useful purpose makes me happy. The Ohio valley is starting to catch up with other parts of the country and is at the beginning of a big box store contraction. There are a few of these things that do well, mainly at the interchanges of highways, and the rest are failing. Might be some data points to bring up the next time I talk to people on the planning commission.
It's been pointed out before that the rise of megachurches was directly linked with the fall of K-marts and smaller big-box stores that were crushed by the Walmart supercenters opened up elsewhere. Three of my friends are involved with a church in Bellingham that used to be a JC Penney.
About 6(?) years ago a church moved into a building in an area funded by County taxpayers in San Diego that caused a ruckus over where tax exempt organizations were taking advantage of the taxpayers. I'm not sure what happened to them, and a quick googling shows nothing but the stadium nonsense in SoCal. Now they are looking at these places as areas to build more apartments and affordable housing as all the transport etc is already in place.