In connection with this subject, there is one other inquiry of importance. It concerns not only the harmony of the gospel system with the nature of things, but likewise the harmony of apostolic practice with what has been shown to be necessary in order that the truths of the gospel might produce their legitimate effect upon the mind. It has been demonstrated that a sense of man's guilt and danger must exist in the mind before there can be gratitude and love to the being who removes the guilt and rescues from the danger. It has likewise been noticed, as a self-evident principle, that before repentance there must be conviction of sin. A sense of guilt and error must necessarily precede reformation of life. A man cannot conscientiously turn from a course of life, and repent of past conduct, unless he sees and feels the error and the evil of that course from which he turns. To suppose that a man would turn from a course of life which he neither thought nor felt to be wrong or dangerous, is to suppose an absurdity; it follows, therefore, that the preacher's first duty, in endeavouring to reclaim men to holiness and to God, would be, in all cases, to present such truths as were adapted to convict their hearers of their spiritual guilt and danger. As God has constituted the mind, repentance from sin and attainment to holiness would for ever be impossible on any other conditions. But the same truths would not convict all men of sin. In order to convict any particular man, or class of men, of sin, those facts must be fastened upon with which they have associated the idea of moral good and evil, and concerning which they are particularly guilty. Thus, in the days of the apostles, the Gentiles could not be convicted of sin for rejecting and crucifying Christ; but, it being a fact in the case of the Jews that all their ideas of good and evil, both temporal and spiritual, were associated with the Messiah, nothing in all the catalogue of guilt would be adapted to convict them of sin so powerfully as the thought that they had despised and crucified the Messiah of God. On the other hand, the heathen, upon whom the charge of rejecting Christ would have no influence, could be convicted of sin only by showing them the falsehood and folly of their idolatry; the holy character of the true God, and the righteous and spiritual nature of the law which they were bound to obey, and by which they would finally be judged. The first preachers of the Gospel, therefore, in conformity with these principles, would aim first, and directly, to convince their hearers of their sins, and in accomplishing this end, they would fasten upon those facts in which the guilt of their hearers more particularly consisted. And then, when men were thus convicted of their guilt, the salvation through Christ from sin, and its penalty, would be pressed upon their anxious souls; and they would be taught to exercise faith in Jesus, as the meritorious cause of life, pardon, and happiness.