A.T. Robertson Commentary 1 John 2:26

"These things have I written unto you concerning them that would lead you astray." — 1 John 2:26 (ASV)

Concerning them that would lead you astray (περ των πλανωντων υμας). "Concerning those that are trying to lead you astray" (conative use of the present active articular participle of πλαναω. See 1:8 for this verb. John is doing his part to rescue the sheep from the wolves, as Paul did (Acts 20:29).