My two cents worth..........
Freedom to express oneself, even if it upsets others in any way, is to my mind, the only stand to take upon this.
To me, that is what it means! If others are troubled by it, speech and expression, they can apply reason and rationality, sifting out the metaphysical, the affective value judgements, from what is objectively being said, and then make up their own minds.
This freedom though, as others here have pointed out, often extends to plain insults or plainly derogatory statements... Well - they are just that, affective and meaningless... sticks and stones may break bones... but insults and derogatory statements should not hurt anyone.
Of course the young and unsophisticated have to be protected, especially in forums such as this.
Insults and derogatory statements can be hurtful, as others here have already implied, if the person they are directed at cannot appreciate them for what they... rubbish.
As to Religion... that is an affective concept in itself, so sometimes sensibilities and personal faith are going to be challenged.
That is as it should be.
A Faith that cannot stand up to being challenged, is 'blind' faith, and not really worth anything beyond the person expressing it. If someone gives up questioning themselves, that is their loss, in my humble opinion.
The strongest Faith is the one that knows it cannot be challenged objectively.
One can never DISPROVE an individual's personal faith. That is why it is defined as a Faith.
If there was evidence for that faith beyond the heart and soul of the individual, Faith would not be necessary. You would be dealing with objectivities, facts. The word would be redundant.
The only place a Faith is validated is within one's heart and soul... that is where it should be questioned... constantly... but then, that is just my personal perception concerning an affective quality such as having a religious faith!
Everyone should be allowed the freedom to follow their faith, whatever that faith may be.
We can then judge the actions of those people objectively, and that way perhaps assess the objective value of their faith beyond their declarations of it... especially if it is resulting in collective actions and behaviours.