William Kelly · 1 Thessalonians 5.

The apostle, however, immediately and carefully declares how different is the lot of the faithful. "But ye, brethren, are not in darkness, that the day should overtake you as a thief; for ye all are sons of light and sons of day: we are not of night nor of darkness" (vers. 4, 5). He is not afraid that it would endanger the young believers in Thessalonica, or any others, to know how grace had distinguished them from the rest of mankind, his very aim here, as elsewhere, is to impress this distinction on them ineffaceably. He says, first, that they were not in darkness, that the day should surprise them as a thief; secondly, that they all were sons of light and sons of day. Not only were they unlike the world as in darkness and the objects of the Lord's judgment, but positive sharers of divine nature and blessedness. Indeed, such is the peculiar being of God's children generally, as he adds, "we are not of night nor of darkness." We are of God, Who is light, and in Whom is no darkness at all.