Confidence in an unfaithful man in time of trouble is like a bad tooth and a foot out of joint. (Proverbs 25:19)
Sometimes one needs to consider a little preventive medicine. The unfaithful do not rise to the occasion, they fall when the occasion arises. Therefore a leader must either work with the unfaithful to make him or her faithful or the unfaithful must be replaced. Time and chance does not fix it. Apathy or even patience does not cause it to change. I have mistakenly held on to the unfaithful thinking that I was being faithful to them. I was wrong, both for their sake, my own sake and the sake of others. Once unfaithfulness is evidenced, it must immediately be dealt with and if not able to be corrected, it must be rooted out. Ignoring it or hoping that it will go away only hinders the one who is unfaithful. I have also found that the only safeguard against unfaithfulness is accountability. The faithful embrace it, while the unfaithful will be exposed by it.