- Argue that a "lifestyle" or inclination even if the specific acts have not occurred is sinful or
- Prove that specific acts occurred
The key to this defense is that you are not obligated to make "statements against interest". You never lie, you simple indicate the prosecution is obligated to prove grounds for their case. In are fornication example, a specific act of fornication at a specific time not a general suspicion of fornication. Churches with a strong judicial history will not excommunicate for refusing to make statement against interest, and if you come from a catholic or presbyterian tradition make sure to quote these references. Those with a weak one may consider it, but this is America people are going to be mighty reluctant to convict just because you "plead the 5th". If you are to be excommunicated make sure its for refusing to make statements against interest not for the specific charge. You should understand however that you will be under intense pressure to make such statements; the philosophy of most churches is masochistic arguing you should welcome their authority. Expect arguments like: "You aren't submitting to biblical authority", "this isn't a court you can't refuse to confirm or deny facts"... the point is to make your stand here not on the issue. Ultimately this defense is going to hinge on the fact that the bible supports a despotic form of government while Americans tend to believe in a democratic form. You are unlikely to be excommunicated for things that most people believe are your within your rights (like refusing to plead).
A more complex example of this working is homosexuality. In general churches that excommunicate homosexuals have one of two beliefs. The first view is that homosexuality is a sin in and of itself. That is it is a perversion born of sin, like drug addition alcoholism or a gambling addiction. A person is a homosexual because they have cultivated a taste for perversion. The second view is that homosexuality itself is not sinful. Specific sex acts (like "topping" during anal sex) are sinful.
- Force the church to come down clearly on one side or the other. In general most churches in today's world will be very reluctant to openly take the first position. They by in large believe it, but they won't admit to believing it as it so politically incorrect.
- If they argue the first case make them prove the process of cultivation and perversion. That is make them prove the pattern of acts leading to the inclination
- If they argue the second case force them to prove a specific act with a specific person at a specific time.
Larry is a 17 year old boy whose mother caught him with gay porn. Larry is brought before the pastor who argues that Larry needs to undergo transitioning to deal with sinful, homosexual impulses. Larry has no desire to undergo a brainwashing procedure with a one of three chance of success and a virtual certainty of serious psychological damage and harm. On the other hand he doesn't want to lie. He also doesn't want to be excommunicated.
So the first step for Larry is to declare that while he is sexual excited by men he is not a homosexual. He is in fact still a virgin, has never engaged in any sort of extreme sexual behavior and believes himself to simply be sexual immature perhaps developing a bit late. He won't know for a few more years. He also repents for masturbation.
The pastor now is on the spot. If he declares that a sexual taste for men can develop in the absence of sin then the homosexual inclination is in itself not sinful and thus Larry can't be excommunicated for it. Larry doesn't have a positive obligation to go to Exodus, he's not required to change. The pastor can't prove sex acts (because there aren't any serious ones) and Larry is willing to repent of any petting or whatever he's engaged in.
If on the other hand the pastor isn't willing to agree, he's going to need to prove how Larry cultivated a taste for perversion. That is is the pastor will need to show how Larry choose to develop these abnormal tastes. That's an impossible task.
Either way Larry doesn't get excommunicated while refusing to go to Exodus.