Apocalypse Revealed # 412
412. Then the fourth angel sounded. (8:12) This symbolizes an examination and disclosure of the state of the church in people for whom religion is faith alone, that they are caught up in the evils accompanying falsity and in the falsities accompanying evil.
That this is the symbolic meaning follows from what follows next, understood in the spiritual sense.
To sound a trumpet here means, symbolically, to examine and expose, as in nos. 398, 402, and 407, above.