When two or more people's pursuits of happiness are at odds with each other, they have two basic routes: the zero-sum approach (e.g. fighting), or the collaborative approach.

And when people are trying to come together to form a community or country, it means they are attempting to follow a collaborative approach.

When it comes to physical resources, that might mean sharing or trading.

When it comes to beliefs, we have a couple different options, but oftentimes, the best option is to discuss your beliefs with each other with an open mind, and consider whether their point of view makes more sense than yours does. And if their beliefs do a better job of describing and predicting the world than yours do, than you change your mind. And then, you'll be in agreement, and don't have to be unhappy anymore.