In my experience almost every encounter with non Christians has been infinitely worse than any interactions that I have had with Christians.
Massimo, I can only urge you to think again. I have spent my entire life in a very multicultural/multi faith setting and have experienced nothing like this.
A few years ago, I was very sick and unable to work. It was a Muslim colleague who took the time to drive to my home and see that I was ok. In a different job, it was a Muslim colleague who would bring food in sometimes, specially cooked for us by his wife.
There is a Sikh temple near my home. On Christmas day the man in charge (sorry no idea as to his religious title) would always visit us to wish us the seasons greetings.
When I was ten, a sunday school teacher, herself the mother of young children, went into great detail telling me about the agonies of hellfire that were coming my way. My crime, I did not wish to be in the school play.
I could give you more, but I think my point is made. You just cannot make simple generalizations about such matters, it is extremely unfair and very divisive. Please look again with fresh eyes.