(1.) When they chuse, delight in, and are daily conversant about things that are vain, empty of what is good, and have no tendency to the glory of God, or the spiritual advantage either of ourselves or others. The least vain thought which contains an excursion from our duty to God, brings some degree of guilt with it; but when the mind is wholly taken up with vanity, so that it is turned aside from, or takes no delight in those things that are of the highest importance, this will have a tendency to vitiate the mind, and alienate it from the life of God. (2.) The thoughts of men may be said to be sinful, when they are not fixed, or intensely set, on God and divine things, when engaged in holy duties; and that either, when worldly cares or business, how lawful soever they may be at other times, have a tendency to divert our thoughts from them, being altogether inconsistent therewith. Or when our minds are conversant about spiritual things unseasonably, so as to be diverted from our present design; as, when we are joining with others in prayer, instead of bearing a part with them, in having the same exercise of faith, and other graces, which supposes that our thoughts are employed about the same object with theirs, we are meditating on some other divine subject, foreign to the present occasion. (3.) Our thoughts may be said to be sinful, when they are conversant about spiritual things, without suitable affections, and, consequently, meditating on them as common things, in which we are not much concerned; as when we are destitute of those holy desires after, or delight in God, when drawing nigh to him in holy duties, which his law requires. And this will more evidently appear, when, by comparing the frame of our spirit therein, with what we observe it to be in other instances, we find, that our affections are easily raised, when engaged in matters of less importance, but stupid, and unconcerned about our eternal welfare, in holy duties; which is accompanied with hardness of heart and impenitency, and sometimes with uneasiness and weariness, as though they were a burden to us. On the other hand, our affections may be raised in these duties, and yet we be chargeable with a sinfulness of thought therein; as, [1.] When the affections are raised by things of less importance, while other things that are more affecting, are not regarded. As, supposing a person is meditating on Christ’s sufferings, and he is very much affected with, and enraged at the treachery of Judas, that betrayed him, or the barbarity of the Jews, that crucified him; but not in the least with the sin of the world, that was the occasion of it, or the greatness of his love, that moved him to submit to it. [2.] When our affections are raised in holy duties, and this is all that we depend upon, for justification and acceptance in the sight of God, vainly supposing that our tears will wash away our sins, being destitute of faith in the blood of Christ.