I answer, I. It is a witness that dwells more in the heart than in the head. It is a testimony known by being felt and practised, and not by mere reasoning; the greatest reasoners may miss of it, for it is a testimony written in the heart; and upon this account it has some prerogatives above all the external arguments for the truth of christianity. This inward argument is always at hand, when a believer is in the exercise of his graces, and acting according to his new nature and life: It is an argument that is not lost through the weakness of the brain, the defect of the memory, and long absence from books and study, to which other arguments are liable; it is an argument that cannot be forgotten, while true religion remains in the heart, for it is graven there in lasting characters. Those words of St. Paul to the Corinthians, in his second epistle, chap. iii. ver. 2, 3. have a reference to our present case: _Ye are manifestly declared to be the epistle of Christ ministered by us, written not with ink, but with the Spirit of the living God; not in tables of stone, but in fleshly tables of the heart._ We have a glory in our religion, that distinguishes it from, and advances it above the Jewish dispensation; their law was written in tables of stone, and afterwards Moses wrote it out at large in a book: But ye have something (says the apostle) written in your hearts, that proves the truth of your religion, and of my divine commission, ye who are converted by my gospel; ye Corinthians, who were once vile as the vilest, and upon whose souls the devil, by his temptations and by his power, had inscribed many dark characters, and seemed to seal you over, and mark you to damnation, ye are now the epistle of Christ, ye have those dismal characters rased out, and ye have golden and bright ones inscribed. The image of our Lord Jesus Christ, who is eternal life, appears fairly written on your souls: Ye are the epistle of Christ, and eternal life is begun in you, and thus the gospel witnesses its own truth and divinity by an internal evidence. The gospel of Christ is like a seal or signet, of such inimitable and divine graving, that no created power can counterfeit it; and when the Spirit of God has stamped this gospel on the soul, there are so many holy and happy lines drawn or impressed thereby; so many sacred signatures and divine features stamped on the mind, that gives certain evidence both of a heavenly signet, and a heavenly operator.