"But we have this treasure in earthen vessels, so that the surpassing greatness of the power will be of God and not from ourselves; we are afflicted in every way, but not crushed; perplexed, but not despairing; persecuted, but not forsaken; struck down, but not destroyed; always carrying about in the body the dying of Jesus, so that the life of Jesus also may be manifested in our body." (2 Corinthians 4:7-10, emphasis added)
"Or do you not know that your body is a temple of the Holy Spirit who is in you, whom you have from God, and that you are not your own? For you have been bought with a price: therefore glorify God in your body." (1 Corinthians 6:19-20, emphasis added)
"Abide in Me, and I in you. As the branch cannot bear fruit of itself unless it abides in the vine, so neither can you unless you abide in Me. I am the vine, you are the branches; he who abides in Me and I in him, he bears much fruit, for apart from Me you can do nothing." (John 15:4-5, emphasis added)
What we humans have is capacity, not ability. This comes as quite a shock to us because we thought we could do something. But the Law in its operation on us in our unsaved days got us to admit that we were unable to keep it (and in fact had broken it, making us guilty) with the result that God opened our eyes to see that He had provided a Savior. We gladly received Him because we saw that we needed forgiveness of our sins.
Later, as we tried to keep that Law after Jesus had saved us, we realized something else: we still can't keep the Law. We want to but we don't have the ability so we asked God for help, thinking that somehow if He came alongside us and influenced us we could do it. We find out that that doesn't work, either, though not many followers of Jesus are willing to admit that because they know of nothing in its place. So we try harder and berate ourselves because we're still not doing what we know we ought to do even with Jesus' help.
What is the answer? What's wrong? We have failed to see what we really are and what we were created to be. The human race was created to house the living God. We were not given abilities of our own. We were made to contain the One who is all ability: the Creator and Sustainer of the universe.
The One who gives the Law is Himself the One who comes inside of us to keep it (Ezekiel 11:19-20). God created us with the capacity for Himself, not the ability to do anything as if we had inherent ability. That is why Jesus said, "Apart from Me you can do nothing."
He was talking about fruit bearing and one thing we know is that a branch never bears fruit in and of itself. It has no ability to do that. It was not created as an independent entity. The branch exhibits the fruit but it's not its own fruit that it's producing, it is the fruit of the vine from which it springs. That's why Paul refers to love, joy, peace, patience, kindness, goodness, and faithfulness (not an exclusive list by any means) as the fruit of the Spirit. It's not our fruit. We didn't produce it. We just had the capacity for it and it just shows up on us.
In the same way we are lamps showing forth His light. We're not producing the light we just have the capacity for it and when the power is turned on we shine. The light comes forth from us but we have no light making ability in ourselves. We are in such union with Him that these distinctions become meaningless in the actual living but they are helpful in this discussion as we try to get a handle on things. Jesus is the fruit producer but we're the bearers. He calls both Himself and us the light of the world because He lives in our human form.
All of the Bible illustrations for humanity are symbols of capacity. We are temples of the Holy Spirit. What are temples? The place where a deity dwells. When God commanded Solomon concerning the first temple did He not say that His presence would dwell there? Didn't Jesus say, "And whoever swears by the temple, swears both by the temple and by Him who dwells within it" (Matthew 23:21)? But when the curtain was torn His presence moved out and on Pentecost He came to dwell in hearts of human flesh.
So that's all we are: earthen vessels. What a tremendous relief this is when we realize it! How the burdens come off. We no longer try to keep His commandments, we just continue to surrender our lives to Him on a moment by moment basis and trust Him to keep them in us. We realize that we are not maintaining ourselves but that we are being maintained! We recognize that our union with Him is real and we have found the way to live. We are expressers of Him and He gets all the glory because He deserves it!
And this capacity is for others for the heart of Jesus the Savior is always for others. A lamp doesn't shine for itself but so that others may see. A branch doesn't bear fruit for itself but so that others may enjoy its fruit. A temple exists for the sole reason that people may enter it and worship the one whom it represents. One might say we are more like conduits through whom He flows.