1. It is true in general. (1.) There is that wickedness in our hearts which we ourselves are not aware of and do not suspect to be there; nay, it is a common mistake among the children of men to think themselves, their own hearts at least, a great deal better than they really are. The heart, the conscience of man, in his corrupt and fallen state, is deceitful above all things. It is subtle and false; it is apt to supplant (so the word properly signifies); it is that from which Jacob had his name, a supplanter. It calls evil good and good evil, puts false colours upon things, and cries peace to those to whom peace does not belong. When men say in their hearts (that is, suffer their hearts to whisper to them) that there is no God, or he does not see, or he will not require, or they shall have peace though they go on; in these, and a thousand similar suggestions the heart is deceitful. It cheats men into their own ruin; and this will be the aggravation of it, that they are self-deceivers, self-destroyers. Herein the heart is desperately wicked; it is deadly, it is desperate. The case is bad indeed, and in a manner deplorable and past relief, if the conscience which should rectify the errors of the other faculties is itself a mother of falsehood and a ring-leader in the delusion. What will become of a man if that in him which should be the candle of the Lord give a false light, if God's deputy in the soul, that is entrusted to support his interests, betrays them? Such is the deceitfulness of the heart that we may truly say, Who can know it? Who can describe how bad the heart is? We cannot know our own hearts, not what they will do in an hour of temptation (Hezekiah did not, Peter did not), not what corrupt dispositions there are in them, nor in how many things they have turned aside; who can understand his errors? Much less can we know the hearts of others, or have any dependence upon them. But, (2.) Whatever wickedness there is in the heart God sees it, and knows it, is perfectly acquainted with it and apprised of it: I the Lord search the heart. This is true of all that is in the heart, all the thoughts of it, the quickest, and those that are most carelessly overlooked by ourselves—all the intents of it, the closest, and those that are most artfully disguised, and industriously concealed from others. Men may be imposed upon, but God cannot. He not only searches the heart with a piercing eye, but he tries the reins, to pass a judgment upon what he discovers, to give every thing its true character and due weight. He tries it, as the gold is tried whether it be standard or no, as the prisoner is tried whether he be guilty or no. And this judgment which he makes of the heart is in order to his passing judgment upon the man; it is to give to every man according to his ways (according to the desert and the tendency of them, life to those that walked in the ways of life, and death to those that persisted in the paths of the destroyer) and according to the fruit of his doings, the effect and influence his doings have had upon others, or according to what is settled by the word of God to be the fruit of men's doings, blessings to the obedient and curses to the disobedient. Note, Therefore God is Judge himself, and he alone, because he, and none besides, knows the hearts of the children of men.