An Edward's quote regarding true and false religion...

". . .till we have learned well to distinguish between true and false religion, between saving affections and experiences, and those manifold fair shows, and glistering appearances, by which they are counterfeited; the consequences of which, when they are not distinguished, are often inexpressibly dreadful. By this means the devil gratifies himself, by bringing to pass, that that should be offered to God, by multitudes, under a notion of a pleasing acceptable service to him, that is indeed above all things abominable to him. By this means, he deceives great multitudes about the state of their souls; making them think they are something, when they are nothing; and so eternally undoes'em: and not only so, but establishes many, in a strong confidence of their eminent holiness, who are in God's sight, some of the vilest hypocrites. By this means, he many ways, damps and wounds religion in the hearts of saints, obscures and deforms it by corrupt mixtures, causes their religious affections woefully to degenerate, and sometimes for considerable time, to be like manna, that bred worms and stank . . . And by what is seen of the terrible consequences of this counterfeit religion, when not distinguished from true religion, God's people in general have their minds unhinged and unsettled, in things of religion, and know not where to set their foot, or what to think or do; and many are brought into doubts, whether there be anything at all in religion; and heresy, and infidelity, and atheism greatly prevail." Jonathan Edwards, preface to Religious Affections, 1746