John 8:44
John 8:4444You belong to your father, the devil, and you want to carry out his desires. He was a murderer from the beginning, refusing to uphold the truth, because there is no truth in him. When he lies, he speaks his native language, because he is a liar and the father of lies.
JWs draw on to characterise Satan as a personal, intelligent enemy — the original murderer and the father of the lie. The verse anchors a robust JW demonology that takes Satan's reality seriously, sometimes more seriously than many nominally Christian groups do. It also feeds the rhetorical move of attributing doubts about the organisation, attractive worldly options, or any drift toward "apostasy" to Satan's direct working. The diagnostic is: if Satan is the father of the lie, then anything that contradicts the channel of truth (the organisation) must be ultimately satanic in origin.
Jesus' indictment in names Satan precisely — a murderer from the start, no truth in him, native speaker of falsehood, father of lies. That is the full inventory: deception, accusation, murder, hatred of truth. On the doorstep, this verse is one of the cleanest scriptural reasons to refuse the rhetorical move that attributes every doubt to Satan. The text says Satan deals in lies; it does not say Satan personally manufactures every individual hesitation in every Witness's heart. Pair with and (Satan prowls and roves — locomotion, not omnipresence) and (resist the devil and he will flee — implying he can flee, therefore is not omnipresent). Use the verse to take Satan seriously as a real liar without granting him divine attributes. The Witness who has been taught to fear that her honest questions are satanic needs to hear scripture restoring Satan to his actual creaturely scale.