Galatians 6:7-8

Do not be deceived, God is not mocked; for whatever a man sows, that he will also reap. For he who sows to his flesh will of the flesh reap corruption, be he who sows to the Spirit will of the Spirit reap everlasting life.

The flesh likes its way and is selfish and is never satisfied. The more we feed the flesh, the less satisfied it is. The spirit grows with the nourishment of the Word of God, and this growth brings about health and prosperity as we gain knowledge from the word we learn how to be free of the corruptions of the flesh.