Lying is the most prominent sin of mankind, and because truth is the most essential characteristic of Christianity, in Ephesians 4:22-29 which lists the remnants of the old man that are sins that are most likely to creep back into the Christian’s life, Paul mentions lying first.
20 But you did not learn Christ in this way, 21 if indeed you heard Him and were taught in Him, just as truth is in Jesus, 22 to put off the old man, which pertains to your former manner of life, the one being corrupted according to the lusts of deceit, 23 and to be renewed by the Spirit controlling your mind, 24 and putting on the new man, the one according to God having been created in righteousness and sanctity of the truth. Ephesians 4:20-29 (translated from the NA28 Greek text) (Read verses 25-29 on the site)