Human nature in its fourfold state ... In several practical discourses

And, (1.) Thy obedience must be perfect, in respect of the principle of it; that is, thy soul, the principle of action, must be perfectly pure, and altogether without sin. For the law requires all moral perfection; not only actual, but habitual, and so condemns original sin; impurity of nature, as well as of actions. Now, if thou canst bring this to pass; thou shalt be able to answer that question of Solomon's, so, as never one of Adam's posterity could yet answer it, Prov. xx 9 Who can say, I have made my heart clean? But if thou canst not, the very want of this perfection is a sin; and so lays thee open to the curse, and cuts thee off from life. Yea, it makes all thine actions, even thy best actions sinful, for who can bring a clean thing out of an unclean? Job xiv. 4. And dost thou think by sin, to help thyself out of sin and misery? (2.) Thy obedience must also be perfect in parts. It must be as broad as the whole law of God: if thou lackest one thing, thou art undone; for the law denounceth the curse on him that continueth not in every thing written therein, Gal. iii. 10. Thou must give internal and external obedience to the whole law; keep all the commands, in heart and life. If thou breakest any one of them, that will insure thy ruin. A vain thought, or idle word, will still shut thee up under the curse. (3.) It must be perfect in respect of degrees; as was the obedience of Adam, while he stood in his innocence. This the law requires, and will accept of no less, Mat. xxii. 37. Thou shalt love the Lord thy God, with ⟨p. 120⟩all thy heart, and with all thy soul, and with all thy mind. If one degree of that love required by the law, be wanting; if each part of thy obedience be not screwed up to the greatest height commanded; that want is a breach of the law, and so leaves thee still under the curse. One may bring as many buckets of water to a house that is on fire, as he is able to carry, and yet it may be consumed; and will be so, if he bring not as many as will quench the fire. Even so, although thou shouldst do what thou art able, in keeping the commands; if thou fail in the least degree of obedience which the law enjoins, thou art certainly ruined for ever; unless thou take hold of Christ, renouncing all thy righteousness as filthy rags. See