Refer to this thread here-
http://www.greekchat.com/gcforums/showthread.php?t=5632
There are a few posts from fellow Michiganders there as well as info about OES.
AFAIK OES contradicts Christianity about as much as reading Harry Potter does. A lot of the religious zealots out there believe that all fraternal societies, college GLOs included, have nefarious purposes and satanic undertones.