'Wilderness' signifies something with little life in it, as described in the internal sense in Luke 1:80 'Wilderness' signifies somewhere there is no good because there is no truth. 'Wilderness,' as in Jeremiah 23:10, signifies the Word when it is adulterated.

(Odkazy: Arcana Coelestia 1927)

398. The first angel sounded. (8:7) This symbolizes an examination and exposure of the state of life and its character in people caught up interiorly in that faith.

To sound a trumpet means, symbolically, to examine and expose (no. 397). The sounding of the first angel means an examination and exposure of the state of the church among people caught up interiorly in that faith, because it produced its effect on the earth, as said next, and the sounding of the second angel produced its effect on the sea; and throughout the book of Revelation, when both earth and sea are mentioned, the whole church is meant - the earth meaning the church composed of people concerned with its internal elements, and the sea meaning the church composed of people concerned with its external ones. For the church is internal and external - internal in the case of the clergy, external in the laity, or internal in the case of people who study its doctrines interiorly and defend them by the Word, and external in the case of people who do not do that.

[2] Both kinds of people are meant by the earth and the sea in the following places in the book of Revelation:

...that the wind should not blow on the earth, on the sea... (Revelation 7:1)

Do not harm the earth or the sea... (Revelation 7:3)

(The angel coming down from heaven) set his right foot on the sea and his left foot on the earth. (Revelation 10:2, cf. 10:5-6)

I saw a beast rising up out of the sea... and another beast coming up out of the earth... (Revelation 13:1, 11)

Worship (God) who made heaven, the earth, and the sea... (Revelation 14:7)

(The first angel) poured out his bowl upon the earth... Then the second angel poured out his... on the sea... (Revelation 16:2-3)

Earth and sea symbolize the internal and external church, thus the whole church, because people in the spiritual world who are concerned with the internal elements of the church appear to live on dry land, while people who are concerned with its external elements are seemingly at sea, although the seas are appearances caused by the general truths which they possess.

To be shown that the earth symbolizes the church, see no. 285. And that the world does, too, no. 551.