We go through things some times that make us realize that we are not sufficient in ourselves; it is not something we can work up by our own doing. I have been mistaken in this regard for most of my life. 2 Corinthians 3:5 says, " Not that we are sufficient of ourselves to think anything as of ourselves; but our sufficiency is in Christ."
In John 15:5 Christ tells us that He is the vine; we are the branches, we abide in Him and He in us. Without Him we can do nothing. I can muster up a little but it is usually working it up myself. After a short while I tire and realize how useless my effort is for any lasting effect.
We are but yet only beholding, as in a glass, the true glory of the LORD. But as we do we are being changed into the same image from glory to glory, even as by the Spirit of the LORD. Not of ourselves, but of Him. (2 Corinthians 3:18)
He is first and foremost in all things that pertain to any godliness we may claim. He is all in all. Yet He has chosen us in which to place this treasure; in earthen vessels so that the excellency of any power we may have is of Him, not us.
When we feel weak or forsaken for a small season at times, remember that we are always bearing about in our body the dying of the LORD Jesus so that the life of Jesus might be manifest in our body. Then we realize that it all comes from Him! (2 Corinthians 4:10)