You say, that a christian cannot surrender the least tittle of truth which he believes to be the testimony of his God; or do any act which implies such a surrender. And, is it not as unlawful for a particular church, in her ecclesiastical capacity, to surrender any part of that which she hath received, and which she professes as a truth of God's word? Surely, it is no less unlawful. But a church may be justly said to surrender any such part of her profession, when she does not hold it fast. And, it is evident, that she does not hold it fast, when she admits the avowed opposers of it to her sacramental communion: for, in doing so, she in effect tells them and the world, that she does not account their opposition to that article any moral evil, nor the holding of it any duty. She does not require her members to hold it; and, therefore, she must be considered as dropping or surrendering it. For an article, which a church does not require her members to hold, may, indeed, be the private persuasion of individuals, but is no longer any part of her public profession.
See here for some comments from OPC ruling elder Bryan Holstrom making this same argument in the context of the OPC's toleration of baptist members. See here for a general critique of latitudinarianism.