I don't know if I think that's entirely correct -- especially when one factors in American evangelicals. I remember a CNN special with Christiane Amanpour from some years ago, in which, while talking to a girl of about 9 or 10, asking her about her school friends who were Muslim or Jewish. Her answer was a very blase "oh, they go to Hell," as she kept on drawing her picture.
To be honest, I know about this, but it still feels a little unreal. Like another, parallel universe...
I grew up in Germany. The Eastern part of the country is largely non-religious after half a century of communist rule. The SED never prohibited Christian religion or destroyed churches, but Christians could get in trouble easily if they spoke up, and people were encouraged towards atheism. In West Germany, the main religious groups are Catholics and Lutheran Protestants.
The Catholic Church keeps getting in trouble lately for being too conservative (while getting in trouble with the Vatican for being to progressive...) The Maria 2.0 movement is pushing for female priesthood, and pushing hard. And the bishops are under fire for not detecting and stopping child abuse among their priesthood. The Catholic Church keeps loosing members.
The Lutherans (EKD, Evangelische Kirche Deutschlands) are very progressive. They have female pastors and leaders, services for gay couples, and they strive for ecumenical and interreligious dialogue. Doesn't help them much... they are losing members as well.
Other Christian sects exist, but aren't large enough to have any significant social or political influence.
So in short: the two big churches are very diplomatic in their official statements... They might believe that their faith is the "true one" on paper and in private, but they hasten to affirm religious freedom and dialogue in public.
The Muslims, too, present themselves as tolerant and democratic - at least the larger organizations.
The only people who publicly declare that "the others go to hell" are the small groups of extremist Christian evangelicals and salafi Muslims. You meet them in the cities, sometimes, with their info booths and handing out leaflets... But the majority of people dismisses them a crazy extremists.
I am kind of afraid that the extremists will gain more power here, like they do in other countries. But right now , it's pretty relaxed. Admitting that you're an atheist is perfectly fine in most situations. It's more like, if you admit that you're religious, you might be asked "is that just a family tradition or do you really believe in that stuff??"