Then said Jesus to those Jews which believed on him. — Better, to those Jews who had believed Him. The act of faith is mentioned in the previous verse. They are here placed among the believers, with an expression of contrast mixed with, perhaps, something of wonder — Jews and yet believers.
If ye continue in my word. — Or, If ye abide in My word. Comp. Note on John 15:7, where we have the opposite form of the thought, “If ye abide in Me, and My words abide in you.” See also for this idea of abiding, Notes on John 5:37-38. His word was the expression of the eternal truth of God, and He therefore was the one great Teacher. Every other must sit as a disciple at His feet, and continue in daily learning and in daily living to grasp the truth which, in that word and that word only, was revealed to man.
Here, as very frequently, part of the force of the sentence is expressed in the emphasis of the pronoun, “If ye continue in My word.” “Ye, on your part, ye who now believe, but have not the courage to rank yourselves openly among My disciples.”
Then are ye my disciples indeed. — The insertion of “then” does not improve the rendering — “If ye continue in My word, ye are My disciples indeed.” The words imply that He who reads the heart has no confidence in this momentary conviction, which will not stand the test of true discipleship, and all that this includes. (Comp. Notes on John 2:23-25; John 6:66.)