I do believe if each person is sure and true about what s/he really wants to believe and practice, there’s no need for them to personally make other beliefs and believers as well as nonbelievers look bad. And no one would blame or defend someone else just because being on the same boat.
A mature vegetarian or vegan wouldn’t want to make a Muslim feel bad for Eid ul Adha Celebration. A mature Muslim won’t want to convince a Hindu to feel okay to eat some beef. A mature Atheist won’t laugh on strict Muslim, Christian or Jewish’ abstaining from premarital sex or alcohol.
Religious people won’t need to intentionally scorn at pagans. We can be true to ourselves, feeling and deciding that what we believe is the best for us, while at the same time respecting other people’s choices. Some frictions will always happen, yes, but insight, maturity and respect will prevent them from getting worse. That’s our universal mission.