Well, it depends on how you measure faster. Let me also note something important: some of the Pentecostal growth is growth for Pentecostal Christianity, but not Christianity as one religion, since those folks are also leaving (often) some other kind of Christianity, mainly Roman Catholicism.
In fact, and perhaps counterintuitively, the number of new Christians each year outstrips the number of new Muslims, even though the annual growth rate is higher for Muslims (1.81 percent) than for Christians (1.23 percent). Over the last century, Christians have grown at a slower rate than have Muslims, with Muslims increasing from 12 percent to 21 percent of the global population during that time. But this is hardly surprising. Christianity has more total followers than Islam.
From HERE.
