3 For this is [the] will of God, [even] your sanctification, that ye should abstain from fornication; 4 that each of you know how to possess his own vessel in sanctification and honour, 5 (not in passionate desire, even as the nations who know not God,) 6 not overstepping the rights of and wronging his brother in the matter, because the Lord [is] the avenger of all these things, even as we also told you before, and have fully testified.
Matthew Henry's Commentary on 1 Thessalonians 4:3-6
Commentary on 1 Thessalonians 4:1-8
(Read 1 Thessalonians 4:1-8)
To abide in the faith of the gospel is not enough, we must abound in the work of faith. The rule according to which all ought to walk and act, is the commandments given by the Lord Jesus Christ. Sanctification, in the renewal of their souls under the influences of the Holy Spirit, and attention to appointed duties, constituted the will of God respecting them. In aspiring after this renewal of the soul unto holiness, strict restraint must be put upon the appetites and senses of the body, and on the thoughts and inclinations of the will, which lead to wrong uses of them. The Lord calls none into his family to live unholy lives, but that they may be taught and enabled to walk before him in holiness. Some make light of the precepts of holiness, because they hear them from men; but they are God's commands, and to break them is to despise God.