Passage
And now I have told you before it come to pass: that when it shall come to pass, you may believe.
And now I have told you before it come to pass: that when it shall come to pass, you may believe.
John 14:27 Peace I leave with you: my peace I give unto you: not as the world giveth, do I give unto you. Let not your heart be troubled: nor let it be afraid.
John 14:28 You have heard that I said to you: I go away, and I come unto you. If you loved me you would indeed be glad, because I go to the Father: for the Father is greater than I.
John 14:29 And now I have told you before it come to pass: that when it shall come to pass, you may believe.
John 14:30 I will not now speak many things with you. For the prince of this world: cometh: and in me he hath not any thing.
John 14:31 But that the world may know that I love the Father: and as the Father hath given me commandments, so do I. Arise, let us go hence.
The verse centers on "told", "before", "come", "pass", "shall", and "believe". It is saying that the verse draws attention to "told" and "before", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 28's "You have heard that I said to..." into verse 30's "I will not now speak many things...", so "told" and "before" belong inside that flow. In John context, the local focus is the identity of Jesus, new birth, eternal life, and belief and unbelief.
A plain takeaway is to answer the verse's own emphasis on "told" and "before" with trust shaped by these words, not by a vague optimism outside the passage.