That occasions true tolerance. All religions, whether pluralistic or exclusivist, claim to be right in some respect in which others are wrong. Pluralism claims that the exclusivity of some religions is wrong. Pluralists would have all people somehow be true to themselves, keeping their own religious traditions. But when a religious tradition indicates that it is the only way to salvation, it must discard that part of its belief system.
Ecumenism celebrates religious belief in the abstract.
And that is the puzzle. Without making a judgment on the truth of any particular religion, if a religion believed that I, as a non-believer, was in danger of the fires of Hell, I would find it natural for them to share their message with me. Of course, I would hope that they would do this in a considerate, non-coercive way. If people truly believe that their religion is right, and others are wrong, they have a moral obligation to try to share their religion. Not to do so would in fact be inconsiderate.