“The doctrine of the church is the entire and uncorrupted doctrine of the law and gospel concerning the true God, together with his will, works, and worship; divinely revealed, and comprehended in the writings of the prophets and apostles, and confirmed by many miracles and divine testimonies; through which the Holy Spirit works effectually in the hearts of the elect, and gathers from the whole human race an everlasting church, in which God is glorified, both in this, and in the life to come.
This doctrine is the chief and most expressive mark of the true church, which God designs to be visible in the world, and to be separated from the rest of mankind, according to these declarations of scripture: ‘Keep yourselves from idols.’ ‘Come out from among them, and be ye separate.’ ‘If there come any unto you and bring not this doctrine, receive him not into your houses, neither bid him God speed.’ ‘Be ye holy, touch no unclean thing, ye that bear the vessels of the Lord. Come out of her, my people, that ye be not partakers of her sins, and that ye receive not of her plagues.’ (1 John 5:21. 2 Cor. 6:17. 2 John 10. Isa. 52:11. Rev. 18:4.)
God wills that his church be separate and distinct from the world, for the following considerations: First, on account of his own glory; for, as he himself will not be joined with idols and devils, so he will not have his truth confounded with falsehood, and his church with her enemies, the children of the devil; but will have them carefully distinguished and separated. It would be reproachful to God to suppose that he would have and acknowledge as his children, such as persecute him; yea, it would be blasphemy to make God the author of false doctrine, and the defender of the wicked; for ‘what concord has Christ with Beliel [sic].’ (2 Cor. 6:14.)
Secondly, on account of the consolation and salvation of his people; for it is necessary that the church should be visible in the world, that the elect, scattered abroad among the whole human race, may know with what society they ought to unite themselves, and that, being gathered into the church, they may enjoy this sure comfort, that they are members of that family in which God delights, and which has the promises of everlasting life. For it is the will of God that all those who are to be saved, should be gathered into the church in this life” (Zacharias Ursinus, Commentary on the Heidelberg Catechism, pp. 1-2).
Quotes (like this one by Ursinus) that speak of actually making judgments about the spiritual state of others, and that imply a clear Scriptural antithesis between the true gospel and all false gospels, between the true God and all false gods, between the true Christ and all false christs, and between the true Holy Spirit and all false spirits, brings to my mind the “mental muddiness” of the typical tolerant Calvinist. For The Great Whore has this amazing proclivity to bedazzle and becloud the tolerant Calvinist into a “charitable” view of her “doctrinal imperfections.” For the typical tolerant Calvinist, the Great Whore is NOT infected with theologically damnable and pernicious venereal plagues, but rather, spotted with mere “theological blemishes.” The abominations in her cup are NOT so abominable for them to come out of her, lest they share in her sins and receive of her plagues. Many tolerant Calvinists even bicker and fight with the Great Whore. But despite this, they apparently find something sufficiently amiable in her for them to admit spiritual oneness with her.
“And after these things I saw another angel coming down out of Heaven having great authority, and the earth was lighted up from his glory. And he cried in a strong, great voice, saying, Babylon the great has fallen! It has fallen, and it has become a dwelling-place of demons, and a prison of every unclean spirit, and a prison of every unclean bird, even having been hated, because of the wine of the anger of her fornication which all the nations have drunk, even the kings of the earth have committed fornication with her; and the merchants of the earth became rich from the power of her luxury. And I heard another voice out of Heaven saying, My people, come out of her, that you may not share in her sins, and that you may not receive of her plagues; because her sins joined together, even up to Heaven, and God remembered her unjust deeds” (Revelation 18:1-5).