The Lord gives the reason why the righteous need not fear. Theirs is a confidence in the eternities, theirs is a confidence in their ultimate salvation. Just as the Lord contrasted the seeming permanence of the world with the real permanence of his gospel, so here he contrasts the apparent favored state of the powerful (those who would revile) with the ultimate salvation. There may be those who are powerful now - so powerful that it might seem nothing could stand against them, yet "the moth shall eat them up like a garment." Their wealth and power are transitory. The blessings reserved for the righteous are forever.