3. You may hence perceive also how we are said to be "sealed" by the Spirit, Eph. i. 13; Rom. viii. 9; Eph. iv. 30: even as a man's seal doth signify the thing sealed to be his own; so the "Spirit of holiness in us," is God's seal upon us, signifying that we are his, 2 Tim. ii. 19. Every one that "hath the Spirit," is sealed by having it: and that is his evidence, which, if he discern, he may know that he is thus sealed.
4. Hereby also you may see what the "earnest and first-fruits of the Spirit" is, 2 Cor. i. 22: the Spirit is given to us by God, as the earnest of the glory which he will give us. To whomsoever he giveth the spirit of faith, and love, and holiness, he giveth the seed of life eternal, and an inclination thereto, which is his earnest of it.
5. Hereby also you may see how the Spirit witnesseth that we are the children of God. The word "witness" is put here principally for evidence: if any one question our adoption, the witness or evidence which we must produce to prove it, is the "Spirit of Jesus sanctifying us," and dwelling in us: this is the chief part (at least) of the sense of the text, Rom. viii. 16. Though it is true, that the same Spirit witnesseth by (1.) Showing us the grace which he hath given us; (2.) And by showing us the truth of the promise made to all believers; (3.) And by helping us from those promises to conclude with boldness, that we are the children of God; (4.) And by helping us to rejoice therein.
II. I have been the longer (though too short) in acquainting you with the office of the Holy Ghost, (supposing your belief that he is the third person in the Trinity,) because it is an article of grand importance, neglected by many that profess it, and because there are so many and dangerous errors in the world about it. Your great care now must be, 1. To find this Spirit in you, as the principle of your operations: and, 2. To obey it, and follow its motions, as it leadeth you up to communion with God. Of the first I have spoken in the first chapter. For the second, observe these few directions.