The reading from Isaiah focuses on future, universal recognition of the sovereignty of the God of Israel. God’s mountain refers to the site of the temple, yet the image evokes more than location. Not only God’s dwelling place, but also as the place from which the divine King exercises dominion through law-giving and judgment, the mountain represents God’s sovereign rule. In time, the kingship of God will extend beyond Israel as other nations receive both instructions previously reserved for Israel and the benefit of God’s just judgment. Enlightened by God’s instruction and obedient to God’s judgment of conflicts, the nations will have no need to resort to war.
Having exhorted the Roman Christians not to conform themselves to the present age, but to allow their minds to be transformed (Romans 12:2), Paul has insisted they must love one another, for “love is the fulfillment of the law” (13:10). Paul now places his plea within the context of God’s plan: moral transformation is both necessary and urgent, for the dawn of salvation has begun. To remain in former ways is to be caught “asleep” as the sun rises. Transformation comes about by putting on the “armor of light,” Christ himself (“put on the Lord Jesus Christ”), who protects against the seductions of the flesh, physical or social. Thus, it is Christ who brings about in the believer this saving transformation.
Jesus’ speech picks up this same idea of not being caught off guard when he returns. Just as the flood brought with it a sudden change from life as usual to judgment, so it will be when the Son of Man comes back. Now is the time to make whatever changes need to be made in one’s life. As in the Pauline passage, there is a union of eschatology and ethics—one must live in a way that is fitting for the reign of God. There will come a time when it will be “too late,” when the time of preparation will have passed.