A.T. Robertson Commentary 1 Thessalonians 4:5

"not in the passion of lust, even as the Gentiles who know not God;" — 1 Thessalonians 4:5 (ASV)

Not in the passion of lust (μη εν παθε επιθυμιας). Plain picture of the wrong way for the husband to come to marriage.

That know not God (τα μη ειδοτα τον θεον). Second perfect participle of οιδα. The heathen knew gods as licentious as they are themselves, but not God. One of the reasons for the revival of paganism in modern life is professedly this very thing that men wish to get rid of the inhibitions against licentiousness by God.