Albert Barnes 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 lust of concupiscence. In gross gratifications.

Even as the Gentiles. This was, and is, a common vice among the Gentiles. (Romans 1:29; Ephesians 4:17, 19). And reports from missionaries everywhere corroborate this.

Which know not God. (See Romans 1:21, 28; Ephesians 2:12).