While people have a right to their beliefs, their belief is not proof that they are right. Religious people believe the contentions of their creed are true, but have no compelling evidence or irrefutable argument that supports their claims.
Nonbelievers should not refrain from challenging religious beliefs especially when the believers are seeking to impose their unproven tenets on all and sundry. Their beliefs are truly nothing more than opinions. Fervently held opinions remain opinions nonetheless.
No person or group has any rightful claim that their opinions should be forced upon others with different opinions. Once the discussion shifts from what people know to what their opinions are the best we can hope for is agreeable disagreement where opinions clash. In the absence of evidence, there is not sound way to resolve differences of opinion.
That being said, taking offense because somebody expresses an opinion one does not share is both churlish and childish.
