Quarrel with a friend - and you are both wrong.
A vessel is formed from a lump of clay with care, however, it is the empty space within the vessel that makes it useful.
He does not struggle with anyone - thus no one can vanquish him.
Be Content with what you have; rejoice in the way things are. When you realize there is nothing lacking, the whole world belongs to you.
When much virtue is achieved, nothing is not overcome.
When you have accomplished your goal simply walk away. This is the path way to Heaven.