The Bible has the answer. 1 Timothy 5:20 (NKJV) "Those who are sinning rebuke in the presence of all, that the rest also may fear." The exposure of fallen ministers occur because like all sinners, the Lord does it to spare them the penalty of hell. Exposure is the last line. In the OT, David committed adultery with Bathsheba (see 2 Samuel 11). When David's men were fighting, it appears that David decided to "conveniently" stay behind. Took a nap and at the "appointed time,"

Colossians 4:6 (NKJV) "Let your speech always be with grace, seasoned with salt, that you may know how you ought to answer each one."...

Revelation 12:7-11 (NKJV) And war broke out in heaven: Michael and his angels fought with the dragon; and the dragon and his angels...