The Measure:
"...If you abide in My word, then you are truly disciples of Mine; and you shall know the truth and the truth shall set you free."
John 8:31, 32
The Proof:
"If you abide in Me, and My words abide in you, ask whatever you wish, and it shall be done for you. By this My Father is glorified, that you bear much fruit, and so prove to be My disciples (or that you bear much fruit and become My disciples)."
John 15:7, 8
The Fruit:
"You did not choose Me, but I chose you, and appointed you, that you should go and bear fruit, and that your fruit should remain, that whatever you ask of the Father in My name, He may give it to you."
John 15:16
"Do you not believe that I am in the Father, and the Father is in Me? The words that I say to you I do not speak on My own initiative, but the Father abiding in Me does His works... Truly, truly, I say to you, he who believes in Me, the works that I do shall he do also, and greater works than these shall he do, because I go to the Father. And whatever you ask in My name, that will I do, that the Father may be glorified in the Son."
John 14:10, 12, 13
"...Truly, truly I say to you, if you ask the Father for anything, He will give it to you in My name. Until now you have asked for nothing in My name; ask and you will receive, that your joy may be full."
John 16:23, 24
"And this is the confidence which we have before (Lit. toward) Him that, if we ask anything according to His will, He hears us. And if we know that He hears us in whatever we ask, we know that we have the requests which we have asked from Him."
1 John 5:14, 15