The Godhead Machine — Thomas K. Carpenter

When religions spread like computer viruses, even atheists have to take notice. An old enemy seizes control of the newly expanded Wiki-religion to create a new world order. To stop him, Zel must join forces with a mega-celebrity doing penance and an orphan girl out for revenge. However, mired on a thawing city in Greenland, she cannot just use her considerable powers to bend reality and fix the problem. Instead, she must turn her greatest weakness - understanding people - into a strength or doom the planet to endless religious war.