I cheerfully join the blue-state sniggering about the Alabama judge who confronts his convicts with a dreadful choice: jail or church. I have not the slightest doubt that this ploy flunks even the Scalia/Volokh standard for constitutionality, although I also suspect it wouldn't be hard to churn up data that regular churchgoers are indeed less likely to wind up in the stony lonesome (whether they find God on the long path to the parole hearing is another issue).
But there is a backcground issue: which church? Wiki reports that there are nine mosques in Alabama. Will Alabama count on them to instill good citizenship? And more: an LDS website counts one Mormon temple in Alabama and six stakes I assume there are plenty of Jews; I find two Lubavitcher congregations. There seem to be more Buddhists than you can shake a stick at (though I would not recommend it). Apparently there is a Gurdwara.
But beyond that. Back twenty years or so ago, I presided over a couple of weddings in my capacity as a former bankruptcy judge--evidently I was specifically authorized in this role by California statute (although I admit I just took their word for it--hey, their wedding, not mine). But more or less the same time, I stumbled on friends/acquaintances who were presiding over weddings and filling in the certificate with just any old church name: evidently the State does not come by to check your accreditation papers. At least California does not; maybe Alabama is different. Does Alabama recognize the church of the Sit-up Cycling? Of What's Happenin' Now?