Think carefully about this verse, as we should, in the context of the surrounding verses.
Mark 6:20 is an extremely telling verse which, as always, is why it is destroyed and messed about with by the modern perverted so-called bibles.
How did "fear" become respect? How did "just" become good, righteous? How did "observe" become protect? How did "did many things" become perplexed, troubled, disturbed?
Get a King James Bible - stop wasting time.