Matt. 16:21-26 shows us not only the subjective gates of Hades coming in to frustrate the building up of the church but also the keys of the kingdom of the heavens which lock these doors and release the building up! We need to use the keys of denying our self, losing our soul life, and taking up our cross! Denying the self mainly relates to our mind, since the self is expressed through the mind with its opinions. Taking up the cross is related to taking up the will of God and not our own will. Losing our soul life is related to the enjoyment of the soul, the pleasure – we need to seek God’s pleasure and His enjoyment!