REV. EDWARD HOARE, M.A. on those troubled by conscience:
That men under such circumstances must seek out a remedy is perfectly obvious, and that there is only one remedy provided by the Lord is equally plain to the student of the Scriptures. That remedy is the free grace of God in Christ Jesus. Let a man be really brought to believe in Him, let him be taught by the Spirit to take home the blessed truth that the whole burden of his blackest sin has been laid on Jesus, and that a pardon, free, immediate, and complete, is granted to the guilty man who stands in Christ, so that “now there is no condemnation to them that are in Christ Jesus, who walk not after the flesh, but after the Spirit,” and that man being justified by faith has peace with God. But then he is taken out of the rank of natural men, and, by the new birth, he is separated unto the kingdom of his Lord; he ceases to be a natural man, and all his peace now flows into his soul through grace.
But suppose this change does not take place, what then? The uneasiness still remains, and the contact with the Gospel only quickens it. The conscious heart therefore is forced back upon its own remedies, and these remedies are of two kinds. The first is Infidelity. The heart struggles to get free from the sense of condemnation by clearing itself if possible from the sense of a God. When conscience convicts of sin, Infidelity steps in and strives to hush its voice, saying, “Thou shall not surely die;” and when the heart persuades the man that he is guilty, he strives to find a refuge in the soothing voice of unbelief, which pretends to teach that there is no God to judge him.
But such a remedy cannot satisfy. There is such a deep conviction of God in the heart, and such unbounded and irresistible proofs of his presence throughout creation, that no man can really rest in such a system. Even Paine himself, when the vessel in which he was crossing to America was on the point of sinking, cried out in his alarm, “Lord Jesus, save me.” And Voltaire, with all his blasphemous daring, six weeks after he had said he should die of glory, did die in all the agonies of despair. The nurse who attended him refused many years afterwards to nurse a devoted Christian Protestant, because she confounded a Protestant with an Infidel, and declared that she never again dare witness such horrors as she had seen in the chamber of Voltaire. So it is told of one who moved not many years back in the centre of Infidel society, that on one occasion, being seized with severe illness at midnight, and dreading the near approach of death, the terror-stricken sufferer sent for an intimate friend, and on his arrival, addressed him in words to this effect. “I fear I am dying, and I am greatly alarmed; so I have sent for you to remind me of the arguments which prove that there is no God.” A fearful confirmation of a remark once made by a Unitarian to a beloved relative of my own—“Our principles are very well while you live, but they won’t do to die upon.”
Thus there is no real peace secured by Infidelity, as it cannot still the conscience, and leaves the heart in as much uneasiness as ever. There appears, therefore, no remedy left for the unconverted man. The Gospel is presented to his view, and the effect is to fill his heart with fear. If he were altogether to accept it, he would be at peace; or if he could altogether reject it, then perchance, he might be at ease; but now there is so much power in it, that he cannot altogether shake it off; while, at the same time, there is so much opposed to all his will in it that he will not by faith embrace it as his own. The only hope that remains in such a case is to discover, if possible, some modification of the Gospel—some system which will profess the grand principles so as not to violate his deep and irresistible convictions, but which at the same time will so modify those principles in their practical application, that it may still the conscience without a change of heart, and give him something that he may rest in as a substitute for peace, while, at the same time, it leaves him still a natural man, with his heart unchanged, and his will unsubdued by the grace that is in Christ Jesus.
Source: POPERY THE ACCOMMODATION OF CHRISTIANITY TO THE NATURAL HEART at https://www.gutenberg.org/files/42280/42280-h/42280-h.htm, p. 5-7