John Calvin Commentary 1 Thessalonians 5:6

"so then let us not sleep, as do the rest, but let us watch and be sober." — 1 Thessalonians 5:6 (ASV)

Therefore let us not sleep. He adds other metaphors closely allied to the preceding one. For as he recently showed that it would by no means be fitting for them to be blind in the middle of light, so he now admonishes that it would be dishonorable and disgraceful to sleep or be drunk in the middle of the day.

Now, as he gives the name of day to the doctrine of the gospel, by which the Christ, the Sun of righteousness (Malachi 4:2), is manifested to us, so when he speaks of sleep and drunkenness, he does not mean natural sleep or drunkenness from wine, but a stupor of mind, when, forgetting God and ourselves, we carelessly indulge our vices.

Let us not sleep, he says; that is, let us not, sunk in indolence, become senseless in the world. As others, that is, unbelievers, from whom ignorance of God, like a dark night, takes away understanding and reason. But let us watch, that is, let us look to the Lord with an attentive mind.

And be sober, that is, casting away the cares of the world, which weigh us down by their pressure, and throwing off base lusts, ascend to heaven with freedom and eagerness. For this is spiritual sobriety, when we use this world so sparingly and temperately that we are not entangled with its allurements.