Charles Spurgeon Commentary Revelation 7:2-3

"And I saw another angel ascend from the sunrising, having the seal of the living God: and he cried with a great voice to the four angels to whom it was given to hurt the earth and the sea, saying, Hurt not the earth, neither the sea, nor the trees, till we shall have sealed the servants of our God on their foreheads." — Revelation 7:2-3 (ASV)

And I saw another angel ascending from the east, having the seal of the living God: and he cried with a loud voice to the four angels, to whom it was given to hurt the earth and the sea, saying, Hurt not the earth, neither the sea, nor the trees, till we have sealed the servants of our God in their foreheads.

Everything exists for the servant of God. Creation is but a scaffold for the Church; and when God's Church is finished, then all may be taken down, but not until then.

And I saw another angel ascending from the east, having the seal of the living God: and he cried with a loud voice to the four angels, to whom it was given to hurt the earth and the sea, saying, Hurt not the earth, neither the sea, nor the trees, till we have sealed the servants of our God in their forehead.

See how other things are protected for the sake of God's people.

The earth and the sea and even the trees have a cordon of safety around them while God's people are being secured. When the Lord Jesus put to sea on the Galilean lake, we read that there were with him many other little ships; and when the calm came for his ship, they were in the calm, too.

And so it is a good thing if you are not in the Church, yet to have some sort of connection with it; it is a great thing for the age to have the Church of God in it, for God will often take care of a nation for the sake of his people. As he would have spared Sodom had there been righteous men found in it, so does he spare nations for the sake of his saints.