That in me ye may have peace (hina en emoi eirēnēn echēte). Present active subjunctive of echō, “that ye may keep on having peace in me,” even when I am put to death, peace to be found nowhere save in me (Joh 14:27).
Be of good cheer (tharseite). Imperative active from tharsos, courage (Act 28:15). A word for courage in the face of danger, only here in John, but see Mat 9:2, Mat 9:22; Mar 10:49.
I have overcome the world (egō, nenikēka ton kosmon). Perfect active indicative of nikaō, to be victorious, to conquer. Always of spiritual victory in the N.T. See 1Jo 5:4. This majestic proclamation of victory over death may be compared with tetelestai (It is finished) in Joh 19:30 as Christ died and with Paul’s hupernikōmen (we are more than conquerors) in Rom 8:37.