Obviously, being blasphemous or posting art that depicts religious entities can offend. But ask yourself, how would an atheist (and not acting in any offensive manner) get treated in a very religious community, such as Saudi Arabia or certain US states?
History provides a simple answer … with zero respect or concern for such atheist. And this practice has been going on for thousands of years.
So although I do not practice this level of offense myself, I do not believe I bear any responsibility for hurting the feelings of theists. Once they tone down their rhetoric, cruelty, even persecution of atheists, then, and only then do they deserve to be treated gently and with respect.
One excuse I hear is “but that is a few in my group, I do not do that myself”. But they are part of that group, they do have voice and power and influence in that group, they should be the ones fighting for their more radical and cruel members to change their ways. And if they do not, then they are enablers, or accessories to such cruelties.
To quote an often used phrase …
If you are not part of the solution then you are part of the problem.