Atheism

Based on my admittedly incomplete readings of the Bible and the Quran, they're pretty close to equivalent. The Quran, if anything, leans harder into telling people not to be a dick.

The practitioners are roughly equivalent, too. You can find peace lovers and warmongers in both. I think the ratios are a bit different, but that's not down to the content of the religion but the context of the believers. Islam is newer, it's dominant largely in areas that are geographically and economically disadvantaged.

It seems to me that people who are doing well, have stable lives, tend to be more peaceful in general. It also seems to me that the older a religion, the more peaceful because the practitioners have had enough time to chill out.