Which is more evil: patriotism or religion? Obviously both are awful ideas that lead to disgusting tribalism and massive disutility. But if you could eliminate one from the world instantly, which one would you pick?
Scenario A: No more patriotism. Earth united under one world government, by competent center-left leaders who mostly respect other cultures, religions, etc. Economic efficiency is vastly improved without stupid trade and human capital barriers, and prosperity ensues, albeit still with some issues of inequality.
Scenario B: No more religion and associated cultural garbage (keeping kosher, religion based repression of women, etc.). People still debate stupid philosophical questions like what it means to be a person (instead of just accepting materialism), but generally the sanity waterline is much higher.