The economic case is somewhat compelling, but I'll set it aside for now, as that is an open and running political dialog playing out with trade agreements, treaties, etc...
Religion, in the US, is entirely optional. We don't have the concept of a "higher authority" codified in the law. We also permit nearly all expression, and in particular, that expression hostile to powerful interests and the government itself.
I often see and hear about things I find completely unacceptable in nations that have not gone there. Religious law, of various kinds, can justify nearly anything. Secular law is similar, but the debate can be meaningful and at least composed of things we can put into a courtroom and reason about.
"God says..." is irrational. We have absolutely nothing on record at all. Thomas Paine details this, and derives the basis for natural rights for us as peer beings in the world, as well as the concept of self-governance in "Rights of Man", and "Age of Reason" --The latter, saw him jailed for a number of years due to how angry Catholics got over that work.
On a basic level, we are all just beings here. If one takes that concept of fundamental equality, and mutual ignorance (no higher authority, no real definitive record or understanding of our origins), a lot of the social progress we've seen are obvious conclusions.
These things are very important to me. I want that basic realization and consideration just as much as I understand my peers here want it, and arguably we all need it too.
Borders do actually compartmentalize the world in ways that compare and contrast these ideas with other, older ideas, and it's very important that the increasingly connected people of the world see all of that play out, so that we may continue to see the social and human benefits expand.
Economics is another discussion, and it has just as much potential to do harm, oppress, etc... as the social issues do, but we are on the upside of social issues, and trading that for improved economics isn't something I feel good about.