Self-distrust

Here's a quote I read in A.W. Tozer's "The Crucified Life":
"So necessary is self-distrust in this conflict, that without it you will be unable, I say not to achieve the victory desired, but even to overcome the very least of your passions. Let this be well impressed upon your mind; for our corrupt nature too easily inclines us to a false estimate of ourselves; so that, being really nothing, we account ourselves to be something, and presume, without the slightest foundation, upon our own strength. This is a fault not easily discerned by us, but very displeasing in the sight of God. For He desires and loves to see in us a frank and true recognition of this most certain truth, that all the virtue and grace which is within us is derived from Him alone, Who is the fountain of all good, and that nothing good can proceed from us, no, not even a thought which can find acceptance in His sight."