The Cross of Christ is the Way into the Kingdom of God

With the cross of Christ, the time has come to gather all nations and tongues (Is. 66:18). The sign of the cross is set forth in the preaching of the Gospel, the declaration of the Lord's glory among the nations (Is. 66:19). Many will come from east and west, and from north and south, and will recline at the table in the kingdom of God (Luke 13:29), but only by the narrow way of the cross. Those who refuse to follow Christ crucified will ultimately find only weeping and gnashing of teeth (Luke 13:28), whereas Christ's disciples, called from all the nations, will eat and drink with Abraham, Isaac, and Jacob in the kingdom of God. They will come into the city of the living God, the heavenly Jerusalem (Heb. 12:22).

Source: LCMS Lectionary Summaries