Suppose you are totally paralyzed and can do nothing for yourself but talk. And suppose a strong and reliable friend promised to live with you and do whatever you needed done. How could you glorify your friend if a stranger came to see you?
Would you glorify his generosity and strength by trying to get out of bed and carry him? No! You would say, “Friend, please come lift me up, and would you put a pillow behind me so I can look at my guest? And would you please put my glasses on for me?”
And so your visitor would learn from your requests that you are helpless and that your friend is strong and kind. You glorify your friend by needing him and asking him for help and counting on him.
In John 15:5, Jesus says, “Apart from me you can do nothing.” So we really are paralyzed. Without Christ, we are capable of no good. As Paul says in Romans 7:18, “Nothing good dwells in me, that is, in my flesh.”
But according to John 15:5, God intends for us to do something good — namely, bear fruit. So as our strong and reliable friend — “I have called you friends” (John 15:15) — he promises to do for us what we can’t do for ourselves.
How then do we glorify him? Jesus gives the answer in John 15:7: “If you abide in me, and my words abide in you, ask whatever you wish, and it will be done for you.” We pray! We ask God to do for us through Christ what we can’t do for ourselves — bear fruit.
Verse 8 gives the result: “By this my Father is glorified, that you bear much fruit.”
So how is God glorified by prayer? Prayer is the open admission that without Christ we can do nothing. And prayer is the turning away from ourselves to God in the confidence that he will provide the help we need.
My addition is from 1 Cor 4:7, “What do you have that you did not receive? If then you received it, why do you boast as if you did not receive it?”