No, orcs aren’t atheists. They worship Sauron and, through him, Melkor/Morgoth.
‘Faithless’ in context means that Sauron doesn’t ‘keep faith’ in the sense of keeping promises and honouring his word. It simply means that he is not to be trusted and isn’t related to religious faith at all.
‘Accursed’ means only the the Valar, after casting Morgoth into the Outer Darkness, gave Sauron - Morgoth’s chief lieutenant - the opportunity to repent. He scorned the offer and so will never get another chance.
Boru
‘Faithless’ in context means that Sauron doesn’t ‘keep faith’ in the sense of keeping promises and honouring his word. It simply means that he is not to be trusted and isn’t related to religious faith at all.
‘Accursed’ means only the the Valar, after casting Morgoth into the Outer Darkness, gave Sauron - Morgoth’s chief lieutenant - the opportunity to repent. He scorned the offer and so will never get another chance.
Boru
‘But it does me no injury for my neighbour to say there are twenty gods or no gods. It neither picks my pocket nor breaks my leg.’ - Thomas Jefferson