I'm an atheist and I have been to mosques. The Blue Mosque in Istanbul was particularly impressive. I've never been to one in Australia but my kids have as part of a school trip learning about religion. So yes you are allowed in.
I was baptised as a Christian, but soon realised it was all garbage. Does that mean I am still a Christian. Is Ayaan Ali Hirsi still a Muslim because she was born one even though she states she is an atheist?
As to the Mohammed the Nice murderer, with that name and coming from Tunisia, he was no doubt born into a Muslim family. That does not mean he is a Muslim now.
However, looking at what's being reported, it looks as though Islam is again the problem.
