It might be well to examine the actions of your life; but as the heart is the spring-head of action, the state of your heart must be the chief object of your inquiry. As to actions, they are neither good nor evil, but as they are the expressions of the heart. Were you to kill a fellow creature, you know, there would be no evil in it provided it was by mere accident, and not from any malicious design, criminal passion, or careless neglect; and if you did ever so much good to your neighbour, yet if it were by accident, and not from design, there would be no goodness in it. It is the disposition of our hearts that denominates our characters in the sight of God. In all your communings, therefore, commune with your hearts.
Perhaps you will say, I find great difficulty in collecting my thoughts, and fixing them upon those things which are of the greatest importance; when I would think, I scarcely know what to think about. Well; give me leave, then, to suggest a few plain questions, which I would earnestly recommend you to put home to your own soul.
First, Does my heart choose and follow after those things which my conscience tells me are right? I can assure you that with many this is not the case. Their consciences tell them that they ought to fear God, to keep holy the sabbath day, to read and hear the word of God, and to perform various other duties; but their hearts are at variance with all these things. Their consciences tell them that they ought not to swear, lie, steal, get intoxicated, cheat their creditors, and ruin their families; but their hearts, nevertheless, are set upon these and many other such wicked courses; and they will pursue them, at all events. Is this the case with any of you? It is a miserable life to have the heart and conscience at variance. You are sensible it is so; and therefore, if any of you are of this description, you labour, I dare say, to lull conscience asleep, that you may enjoy the desires of your heart without interruption from its remonstrances. But this is a desperate way of going on. Conscience will not always sleep; and when it does awake, which perhaps may be upon a death-bed, its voice will be more terrible than thunder, and its accusations more painful than the sting of a scorpion. Did you never see a wicked man upon a dying bed? Perhaps not: possibly you cannot bear such sights, and therefore shun them. There are persons, however, who have; and, witnessing his agony, have longed to alleviate it. The guilt, the fear, and the horror which have appeared in his eyes; the bitter regret that has preyed upon his dying heart; and the forebodings of everlasting misery that seemed to have seized his soul; have wrung their hearts with anguish: but all they could do was to drop an unavailing tear. Given up to the hardness of his heart, even the doctrine of salvation by the blood of the Lamb has had no effect upon him, and he has died in all the misery of despair. Oh that this may not be your end! Yet if such be your life, and you persist in it, there is no reason to expect but that it will.
But it is possible that you may not sustain this character Your heart and conscience may not be at such variance as to give you any considerable pain. If so, let me recommend a second question: Is my conscience instructed and formed by the word of God? Though you may be certain that you are in a wrong course if you live in the violation of conscience, yet you cannot always conclude that you are in a right one when you do not violate it, because conscience itself may err. Saul was conscientious in persecuting the followers of Christ; yet he was one of the chief of sinners for so doing. You may ask, What can a man do but follow that which he thinks to be right? True; but it becomes him to compare his thoughts with the word of God; for we are easily persuaded to think favourably of that conduct which suits our inclinations; and where this is the case, the error of the conscience, instead of excusing the evil conduct, becomes itself an evil.
The consciences of many people tell them, that if they take care of their families, pay every man his due, and attend public worship once or twice a week, this is all that can reasonably be expected at their hands. And I have heard this Scripture passage brought in proof of it, “What doth the Lord thy God require of thee, but to do justly, to love mercy, and to walk humbly with thy God?” But (to say nothing of the love of mercy towards our fellow creatures) to walk humbly with God is a very different thing from the above exercises.
A man’s conscience may be easy, and he may persuade himself that he is in the way to life, while, in fact, he is as far from it as the old Pharisees, against whom the heaviest woes of damnation were denounced. The case of such people seems to be worse, on some accounts, than that of the openly profane: these acting in opposition to their own consciences, as well as to God, a faithful warning sometimes takes hold of their fears; but those, deluded by vain hope, consider all such warnings as inapplicable to them. Both are steering the same course; but the one is impeded by wind and tide, while the other is aided by the current of a perverted conscience. Do not forget to inquire, Is my conscience instructed and formed by the word of God? Perhaps you have not been in the habit of reading that sacred book, or of having it read to you. The neglect of it may occasion your eternal overthrow.
Excerpt from: “Solitary Reflection,” Sermon XI in Sermons and Sketches.
Fuller, A. G. (1988). The Complete Works of Andrew Fuller: Memoirs, Sermons, Etc. (J. Belcher, Ed.; Vol. 1, pp. 222–223). Sprinkle Publications.