New Defender's Study Bible Notes
17:21 within you. The kingdom of God has many aspects and phases (see notes on Matthew 3:2). One first enters the kingdom of God in its spiritual aspect when he or she is born again (John 3:3), and it is this aspect which the Lord emphasized here. “For the kingdom of God is not meat and drink; but righteousness, and peace, and joy in the Holy Ghost” (Romans 14:17). Whenever the disciples of Christ are being persecuted for their faith or are having other difficult times, they find themselves wondering “when the kingdom of God should come” (Luke 17:20). In fact, Christ Himself, urged us to pray: “Thy kingdom come” (Matthew 6:10), and indeed this physical aspect—the kingdom of God on earth, with Christ reigning in righteousness—would indeed come, as He would shortly make clear (Luke 17:24-37). In the meantime, however, as they wait for His coming, believers should remember that His kingdom is already present, in the person of the indwelling Holy Spirit, who is “the earnest of our inheritance until the redemption of the purchased possession” (Ephesians 1:14).