To show that Rev. 3:7 is a quote from the Old Testament and how that adds deeper and more personal meaning to “the key of David” – that it is a quote from Isaiah 22:22. To then show what “the key to the house of David” means and how it is applied in the context of Isaiah 22. How then does that added meaning from Isaiah 22 apply to Christ, as the One who today possesses the key of David? And, how does it apply to all of the true members of God's Church who are Following Christ?