For reporting purposes at Barna, we often combine atheists and agnostics into one group, which we call skeptics. Skeptics either do not believe God exists (atheists) or are not sure God exists, but are open to the possibility (agnostics). Skeptics represent one-quarter of all unchurched adults (25%). Nearly one-third of skeptics have never attended a Christian church service in their lives (31%). That’s nearly double the proportion of “virgin unchurched” who are not skeptics (17%).