Bumpers and rear windows across America are rife with stickers of Calvin either peeing or praying. The original Calvin never paused to pray at a cross in any of the Calvin & Hobbes cartoons, but Christian culture has taken it upon itself to concoct such an image and mass-produce it as a bumper sticker.
The other stickers show Calvin peeing on such assorted effects as American vehicle manufacturers, Osama bin Laden and NASCAR numbers. Bill Watterson never gave his permission for Calvin & Hobbes stickers to be sold but this hasn't deterred their production. Calvin didn't do any territorial/desecratory peeing in the original cartoon either but these bumper stickers are still seen en masse across the red states and in a few blue ones as well.
Maybe Christian culture feels that if Calvin is shown praying instead of peeing then it's okay to nick his image, since it's for a good cause. Maybe Calvin is praying forgiveness for pissing on everything. But why Calvin, of all cartoons? Is it a veiled reference to John Calvin? Or a far-fetched reference to C.S. Lewis? Calvin's mean teacher is named Mrs. Wormwood and Wormwood was a character in The Screwtape Letters and Christian culture reveres C.S. Lewis, but that's about four degrees of separation and this is getting complicated. Would the person who had the idea to make Calvin-cross-stickers please speak up? We'll grant you immunity if you'll just explain yourself.