John Lightfoot on John 8:44

[A murderer from the beginning.] For so the Hebrew idiom would render he was a murderer from the days of the creation. And so Christ, in saying this, speaks according to the vulgar opinion, as if Adam fell the very first day of his creation.

[He abode not in the truth.] I. He abode not in the truth: i.e. he did not continue true, but found out the way of lying.

II. He did not persist in the will of God which he had revealed concerning man. For the revealed will of God is called truth; especially his will revealed in the gospel. Now when God had pleased to make known his good will towards the first man, partly fixing him in so honourable and happy a station, partly commanding the angels that they should minister to him for his good, Hebrews 1:14; the devil did not abide in this truth, nor persisted in this will and command of God. For he, envying the honour and happiness of man, took this command of God concerning the angels' ministering to him, in so much scorn and contempt, that, swelling with most envenomed malice against Adam, and infinite pride against God, he chose rather to dethrone himself from his own glory and felicity, than he would bear Adam's continuance in so noble a station, or minister any way to the happiness of it. An angel was incapable of sinning either more or less than by pride or malice.