"Through God's grace" from a 13th century mystic

I want to start with a long quote from this 13th century mystic. It can be read online here , but the physical book is a worthwhile purchase. I will quote this in full, because it's the struggle in my own faith journey to letting go and letting God. Someone imagines that he can rid himself of his negative qualities by means of his own labor and striving. When he struggles and makes every effort possible only to be disappointed, God says to him, "You thought it would come about through your own power and action and effort. That is the law I have established, that is, that whatever you have you should expend it in My Way -- only then does My grace arrive. "We say to you, 'Travel this infinite road with your own weak legs.' We know that with your weak legs you will never be able to accomplish the journey -- in a hundred thousand years you would not complete even one stage of the journey. But when you make the effort and collapse and fall down, unable to take anoth...