If a person doesn't believe their religion is the best one, they probably shouldn't bother with it. There's a difference between saying your religion is the best and saying that all other religions are bogus and dangerous. I have no problem with people witnessing their faith to me as long as they don't throw the weight of law behind it. As a former atheist, I am no hesitant to point out the logical fallacies of their beliefs if they bring it up.
The acceptance of evangelism is the epitome of freedom.
Most faiths, by their very nature in the monotheistic traditions ONLY believe in their way. At least that's what they held for years. And they did teach that only they have the true interperatations of the various holy books (Old and New Testament, Koran). Every Christian and Jewish sect have that sort of belief.
Polytheistic faiths differed from that. Those faiths believed in their gods but also had room for other people's gods. For example, when the Greeks conquered a people they let the conquered nation keep their gods but made them sort of retrofit the Greek gods into their belief system.
The Greeks ran into resistance from the Jews because the Jews didn't believe in adopting any foreign god. I'm not saying it was right or wrong, but these people clashed based upon this.
Eventually, the Jews managed to divest themselves of the Greeks and the world today is about 1/3 monotheistic in population. By contrast, virtually no one worships Zeus anymore.
And when people used to do business and trade with foreign peoples they used to sort of "trade" gods too. "Oh, you believe in this, we believe in that..."
Of course, in the monotheistic faiths that couldn't be done.
But it's thousands of years after monotheism got started and the whole world isn't converted to it in any of it's major forms.