This forum is the wrong place to seek legal advice. You have not stated enough facts to support the giving of advice to you by any competent lawyer. Nevertheless, before you jump into the pool, know the temperature of the water. Litigation is a very costly means of resolving this problem. Even if you are successful and obtain a judgment, you will likely spend as much as $50,000 to get there. There are a lot of negative aspects to litigating with a family member. Among other things, you can expect that all of your family secrets may be exposed to the public. Got caught jerking off by your brother? etc.
If you get a judgment, what are you going to do with it? Do you have the stomach to enforce it via the filing of a lien against your brother's property?
Think very carefully before you jump into suing your brother. There are other ways to deal with this. For example:
Let him know that if he doesn't stop trashing you to your employees, that you will bring this matter to the attention of the elders (ie., turn him in for gossip and slander).
If that doesn't work, carry out the threat. When you speak to the elders, tell them you want it resolved or else you will take legal action against both your brother and the local congregation. That will get their attention.
If all else fails, and he really is hurting your business enough to make paying the lawyers worth it, then sue him!