A.T. Robertson Commentary 1 John 5:19

"We know that we are of God, and the whole world lieth in the evil one." — 1 John 5:19 (ASV)

Of God (εκ του θεου). See 3:10; 4:6 for this idiom.

Lieth in the evil one (εν τω πονηρω κειτα). Present middle indicative of the defective verb κειμα, to lie, as in Lu 2:12. Πονηρω is masculine, like ο πονηρος in verse 18. This is a terrible picture of the Graeco-Roman world of the first century A.D., which is confirmed by Paul in Romans 1 and 2 and by Horace, Seneca, Juvenal, Tacitus.