One should not be put in jail for saying what one wishes about a religion or its god. However, one had better have a very thick skin, because when someone says insulting things about my religion and my God, I'm quite likely to return the favor.
I HAVE been called (because of my religion) a 'Satanist,' an occultist, a pedophile follower, quite literally a murderer of babies, stupid, illiterate, a lock step cultist, ...well, you name it I've been called that, and my beliefs have been characterized in about every negative way possible...
Here in the US we used to have a principle in law called 'fighting words." Basically it meant that there were some insults so egregious, some words so unacceptable, that a fist planted with force to the nose was considered an appropriate and acceptable response.
This is no longer a good legal defense. However, 'incitement to riot' and "incitement' to violence, or 'incitement' to commit a crime is still a crime in and of itself. More than one 'internet bully' has found that out to his/her cost.
It seems, then, that while I would get arrested for slugging someone who insulted me...and my religion...to that degree, the person who does his level best to incite that reaction might will find himself in front of the judge.
Of course, there is no danger of you (as an example) getting a fist in the nose for being incredibly obnoxious about someone else's religion on this debate forum. Nobody can reach that far, I suppose.
On the other hand, one MIGHT consider what such language might prompt some true believer to do...and figure that 'inciting' that response might not be wise. Or courteous. Or reasonable.
...........or do what you want it to do.
Unless you WANT to incite a response like that, in which case, well.....
Just try using the 'golden rule,' which seems to be a part of most, if not all, human moral/ethical systems.