Thanks @HAWK for the ping. I have plenty to say here. I'll try to keep it short, since I don't want to hog the whole internet.
Without knowing anything specific about the community you are working with, @joseph_bayly, I'll identify where I would generally recommend going with a religious community like the one you describe.
1. Build up a self-differentiated core: If I were you, one of my main goal would be to build up a core of leaders (the term often used in religous circles for "advocates") who are able to maintain an emotional balance amidst chaos. If you are familiar with "systems theory", then you will be familiar with the term "self-differentiation". If not, that is where a person is able to be in a conversation with one emotional foot in and the other outside of the conversation. They can feel connected to the person in front of them, but remain emotionally distant enough to not get caught up in their own emotions and react to statements being made. By being able to step out of their emotions, they are able to maintain a rational perspective that keeps them focused on the issues.
A good sign of someone who is self-differentiating would be someone who stays calm and uses "I" messages. For people who are learning, it's great to teach them to "fake it until you make it". By practicing "I" statements, issue-oriented conversation, and perspective taking, people can grow into that state. For this reason, you will want to have strong rules regarding language. I would suggest that you never allow personal criticism. All criticism must be targetted toward an issue or a person's behavior. Consider the emotional effect on a system (a bunch of readers) who see "Ignore what Jack says because he doesn't know what he's talking about" vs "I have difficulty believing what Jack says here because he is not forthcoming with further explanation of his statements after being asked for it several times".
According to my understanding, when you have a healthy core who is able to self-differentiate, that tone tends to draw the attention of the community. Your leaders start setting the emotional tone for the rest of the community. Their behavior becomes even more authoritative if they prove that they are able to disagree passionately, while maintaining behavior that respects (a great value to promote) those with whom they disagree.
Meanwhile, the less healthy (more reactive) members of the community are naturally going to start pushing back (be prepared for this). This leads us to....
2. Establish and maintain strong behavioral boundaries: I would establish strong guidelines regarding issue- and behavior-oriented language. I would make it clear that you might edit posts that have worthy content but an inappropriate tone, or you might remove such posts and ask for rewrites (which is actually better). Overall, it will seem like you are trying to get everyone to play nice, which is a good perception to have. In reality, you are setting a trap for trolls. By focusing on behavioral expectations that you can point to and say "that crosses the line", you can say that they have chosen to effectively ban themselves since they knew the consequences before they acted.
I would use a demerit system. Give it three colors (green, yellow, red). If someone crosses the line and is in the green zone, well it can happen to the best of us. It's a gentle teaching moment and an opportunity to send a PM, which in itself is a great opportunity to build a relationship. Coach them so they can learn to communicate respectfully (which arguably is something a religious community should be doing anyway). At the yellow level, your language changes. Now you say things such as, "I'm concerned about a pattern of behavior that I see developing in your posts. [This behavior] is counter-productive to community building, and I need it to stop." If it escalates to the red level, it becomes a "this is your last chance" conversation, at which point any push back ends up in a ban.
Banning is good. You want to ban people (believe it or not). If trolls remain in your community, they can unravel it. Boundaries are a non-aggressive way to deal with them. They know which behaviors will end up in a ban before they engage in them. In effect, they ban themselves. (Note: there is an article floating around here somewhere that talks about how problematic members can be identified quickly based on their initial behavior.)
3. Work both openly and behind the scenes: I recommend leveraging both public posts and private messages. When you see behavior that is out of line, make a public note of it. Post a moderator note that says "We are trying to maintain an atmosphere in which people who disagree can do so respectfully. Please remember that name-calling is counter-productive to our goal. In the future, make sure to use respectful language."...or something like that. If you do not make public statements about inappropriate behavior, it will appear that you are turning a blind eye, which will encourage it to continue and flourish. Meanwhile, discuss the issues with the offending member through PMs.
4. Have a policy for alts: One member gets one account, and you must be signed in to post. All additional accounts will be banned, and the original may be banned as well. (Watch those IPs.) I would allow anonymity in the community, and I would allow them to change names (just a personal preference, and people can look up histories to see who people are anyway). Whenever you have a policy like this, make sure you tie it to the vision of the community and its health. You might say, "in the interests of making sure people remain responsible for their own words, which is important in a healthy community, we allow members to only have a single account."
5. Visioncasting: (Hmmm, probably should be #1) I was told once by a wise executive presbyter that as a pastor I needed to cast the vision whenever I got the chance. And when I feel like I can't do it one more time without throwing up, then that's when I needed to redouble my efforts. It's important to constantly remind people of their corporate voyage. You're all in that particular boat together for a reason. Identify it (yep, need an answer to the "reason for being" question asap). Tell the story. Meaning is a narrative construct. The more people hear of the great things they can accomplish by by working together amidst the chaotic waves that would tear everything they've worked so hard to build apart, the more likely they are to work to protect it. Leaders draw people into a meaningful story. Leaders of leaders master the art of storytelling so they can write a meaningful story, re-write it, and make space so that others can thrive in it.
I hope that helps. Let me know if you need me to break anything out.