And now, concerning His words: "And then shall appear the sign of the Son of mam in heaven."  By these words it is meant that when the sun of the heavenly teaching has been eclipsed, the stars of the divinely established law have fallen, and the moon of true knowledge—the educator of mankind—has been obscured; when the standards of guidance and felicity have been reversed, and the morn of truth and righteousness hath sank in night, then shall the sign of the Son of man appear in heaven.

I think we can agree that our modern materialistic and scientific age is the time when heavenly teaching have been eclipsed and divine law has fallen.  The Son of man appering in the heavens sound to me like a prediction very similar to Malichi's prediction of the cominf og the Sun of Righteousness in the end times.