The fool says in his heart "there is no god".
Its a bad translation and taken out of context, so you could point that out if feeling generous. The psalm is about patience, waiting for oppression to end. The psalm is poetic and has poetic license. Its not a denunciation of atheism. If somebody wants to assure themselves that they are wise this is not a foolproof way to do it.
'God' is a term not coined as early as David, and 'Fool' does not really bridge the gap, either. 'God' is translated badly from the Hebrew term 'Elohim' which here refers to the congregation of the righteous. The congregation of the righteous are elohim, and the oppressors are 'Children of men'. Its a poetic usage with precedents in other scriptures. Its not like I'm pulling this out of thin air.
When a religious debate gets heated the above are insults thrown around. You may shrug at them or flag the post for violation of Rule #3.
True or rule 1 or 9 or 8. It depends, and the treatment of insults has changed slightly in the last few years. I think we mostly used rule 1 when I first came to the forum, but the concept is not to insult people in order to make points or to vent. Keeping feelings cool is the goal. Sometimes we don't allow certain language merely because it riles people up.
What is your take on offending language? Where's the limit? Where should be the lawful limit, where the limit on RF?
"You just want to sin." ---
Sounds like ad hominem. It could be a religious debate topic, unless it is personalized to 'You' or 'All of you'. In other words, religious people must discuss whether disbelief comes from the desire to sin. It has to be a permitted topic in a religious forum. Saying "You don't believe because you desire to sin" is not appropriate. Starting a debate in a much less personal way is allowed such as a debate titled "Does disbelief come from a desire to sin?"
"You have no morals." ---
Unfair as character assassination. Religion is about what is moral, so the nature of morality has to be discussed. The nature of morality is also fair game as a philosophical question. Some people do believe that there are no morals without religious faith. They must be allowed to discuss it, however they don't have permission to insult people. This is where rules alone aren't enough to determine what is insult and what is discussion of concepts. It may require intelligent deliberation by staff. The goal is not to get people upset if possible and to keep all of the feet in the pool.
"You are illogical."
Could be ad hominem. Could be insulting. Kind of hard to say without looking at the post.
"You don't know science." ---
Most people don't know Science. Is it an insult? Context matters here. RF does not take a stance on what is scientific....with the exception of Covid 19 resources. RF does not officially declare any support for scientific consensus. We allow crackpot science and real science. We have a paranormal Dir, too.
"You are delusional." --
probably an insult. Could be warned about rules 1 or 3 or 9, maybe 8. Even if the person is obviously delusional its against rules to tell them that they are. There is no way for a person to prove they aren't delusional.