A.T. Robertson Commentary Galatians 5:16

"But I say, walk by the Spirit, and ye shall not fulfil the lust of the flesh." — Galatians 5:16 (ASV)

Ye shall not fulfil (ου μη τελεσητε). Rather, "Ye will not fulfil." Strong double negative with aorist active subjunctive.

The lust of the flesh (επιθυμιαν σαρκος). Bad sense here as usual in Paul, but not so in 1 Thessalonians 2:17; Php 1:23. The word is just craving or longing (from επι, θυμος, yearning after).