Hebrews 12:21 Meaning

19And the sound of a trumpet, and the voice of words; which voice they that heard intreated that the word should not be spoken to them any more:

20(For they could not endure that which was commanded, And if so much as a beast touch the mountain, it shall be stoned, or thrust through with a dart:

21And so terrible was the sight, that Moses said, I exceedingly fear and quake:)

22But ye are come unto mount Sion, and unto the city of the living God, the heavenly Jerusalem, and to an innumerable company of angels,

23To the general assembly and church of the firstborn, which are written in heaven, and to God the Judge of all, and to the spirits of just men made perfect,