John 6:63

Some of Jesus’ disciples turned from Him because they preferred the material realm to the spiritual realm, for which Jesus had an obvious preference. He warned them that the Spirit gives real life (cf. Genesis 1:2; Ezekiel 37:14; John 3:6) whereas the flesh provides nothing of comparable importance. The words that Jesus had spoken to them dealt with spiritual realities and resulted in spiritual life. Furthermore they were words that came from God’s Spirit. Therefore they were extremely important.