Sister, it's wrong to say atheists have the right to voice their opinion on such matters. Allah has the right to be worshipped and how can anyone worship Him if they don't believe in Him? It sounds like you're saying they have the right to transgress upon the rights of Allah.

You think they should be allowed call Muslims to kufr? They should be silenced as they will confuse the weak believers and take them to hellfire with them. And the brother is right in quoting the ayah. Are you arguing against the word of Allah?

All kuffar are like this. They will bring excuses and try to refute any proof you bring them. These kuffar Allah refers to would use the excuse of magic when atheists today would try to refute any signs with "science". You can bring all the evidence in the world but they refuse to believe.

In fact, I was giving my sister dawah and she didn't like what she was hearing so she stuck her fingers in her ears like kuffar mentioned in the Quran. The truth has been made clear from falsehood and they refuse to believe.. They do not want to believe and they listen to shaytan.