How do you hold students accountable for their actions?

Acts of personal control.and distinguish between right and wrong.have faith in god 

The best thing to teach a religion

In the first instance explain the consequences of their actions, or better still get them to do a "self assessment" with your assistance if required. Appeal to their better nature and ask them whether they thought in their "heart of hearts" if their actions were right or wrong. If they say that they think they were in the right, tell them why you think otherwise. If they say that they think that on reflection they were in the wrong, ask them what course of action would have been better. In this manner you are "involving" them and not "condemning" them. Moving forward you can then give examples of how we are all accountable for our actions in life. A motorist may receive a fine for speeding, you as a teacher would face disciplinary action if you didn't do your job properly, etc etc. Once you determine that they understand the point you are making explain what action you are going to take to ensure "accountability" and take that appropriate action. Accountability is equally important for actions which are "good" as well as "bad", sometimes it is easy to come down hard on perceived bad behaviour whilst overlooking good behaviour. Consistency in all you do is paramount.