Why must we pray for the welfare of the church? The church is not a mere human organization; it is the house of God, a divine institution, the body of which Christ is the head. The true welfare of God’s people, even the peace and prosperity of the nations of the world, really depends on the spiritual welfare and security of the church. This of course does not mean merely one denomination, but the whole visible church of God on earth. The Bible teaches that God deals with the nations in accordance with their treatment of his covenant people, his church. God said to Abraham: “I will bless them that bless thee, and curse him that curseth thee; and in thee shall all families of the earth be blessed” (Gen. 12:3) . . . the true welfare and prosperity of the church are very closely related to the peace and prosperity of the nations of the world. It is still true that God will bless them that bless Zion, and curse them that curse Zion.

J. G. Vos, The Westminster Larger Catechism: A Commentary, 531-532.