The readings for the eleventh Sunday after Pentecost are taken from Isaiah 66:18-23; Hebrews 12:4-29; and Luke 13:22-30.
Isaiah, like so many places throughout the Old Testament, emphasizes God’s love for and work among the nations. As Abraham, himself, was called out of the nations and as Isaac was generated from God’s promise, so the Israel/people of God are all the souls regenerated by the Word and Spirit of God in the image of Christ. God does not just make us His own children; He also makes us a priesthood—stewards of His creation and ambassadors of His kingdom (read all of 1 Peter in one sitting to hear this message clearly).
The letter to the Hebrews is altogether a warning to Israel according to the flesh, lest they make the mistake that Esau made. Every human nature is the same as Israel according to the flesh; always turning against God, against neighbor, and against our own soul, life, and future. To keep us from being ruined by the corruption in our human nature, God disciplines us (see 2 Corinthians 1:7-9 and 4:1—5:21 for wonderful clarity about this). Notice how Hebrews also promotes peace with all people, which ambassadors work for.
Luke records the apostles asking if only a few people will be saved. First, remember that God saved everyone through the substitutionary life, death, and resurrection of Jesus. Second, remember that God’s saving work in the life of each person is a life-long work, so we are patient and hopeful and resist making judgments. Jesus commands us to strive to enter by the narrow gate. What is this narrow gate? If God wants all to be saved, why did He make the gate narrow? Take some time here. The wide gate tempts every corrupt human appetite to serve itself (like Esau) and pits us against each other. The narrowness of God’s gate is honesty/humility (same as faith/belief/trust (FBT), same as the yoke of Jesus). When Jesus says that unless we repent and become as a child we cannot enter the kingdom of heaven, He is talking about the honesty/humility of small children and infants. Back again to the theme of being children of God, in truth and forever.