The previous chapter closed with a prayer for their growth in love, with a view to their establishment in holiness. The prayer of a good man avails much in its working; but his prayer of intercession cannot secure the result it seeks without the co-operation of those for whom it is made. Paul, who has besought the Lord on their behalf, now beseeches the Thessalonians themselves, and exhorts them in the Lord Jesus, to walk as they had been taught by him. The gospel, we see from this passage, contains a new law; the preacher must not only do the work of an evangelist, proclaiming the glad tidings of reconciliation to God, but the work of a catechist also, enforcing on those who receive the glad tidings the new law of Christ. This is in accordance with the final charge of the Saviour: "Go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Ghost, teaching them to observe all things whatsoever I have commanded you." The Apostle had followed this Divine order; he had made disciples in Thessalonica, and then he had taught them how to walk and to please God. We who have been born in a Christian country, and bred on the New Testament, are apt to think that we know all these things; our conscience seems to us a sufficient light. We ought to know that, though conscience is universal in the human race, and everywhere distinguishes between a right and a wrong, there is not one of our faculties which is more in need of enlightenment. No one doubts that men who have been converted from heathenism, like the Thessalonians, or the fruits of modern missions in Nyassaland or Madagascar, need to be _taught_ what kind of life pleases God; but in some measure we all need such teaching. We have not been true to conscience; it is set in our human nature like the unprotected compass in the early iron ships: it is exposed to influences from other parts of our nature which bias and deflect it without our knowledge. It needs to be adjusted to the holy will of God, the unchangeable standard of right, and protected against disturbing forces. In Thessalonica Paul had laid down the new law, he says, _through the Lord Jesus_. If it had not been for Him, we should have been without the knowledge of it altogether; we should have had no adequate conception of the life with which God is well pleased. But such a life is exhibited to us in the Gospels; its spirit and requirements can be deduced from Christ's example, and are explicitly set forth in His words. He left us an example, that we should follow in His steps. "Follow Me," is the sum of His commandments; the one all-embracing law of the Christian life.