“God said to Noah, ‘This is the sign of the covenant that I have established between me and all flesh that is on the earth.” – Genesis 9:17
It is not a common place to think about missions and evangelism when it comes to discussing Noah and the great flood. When God destroys all but a handful of people on the planet it seems hard to find a message of outreach buried in the details. In fact, God’s global outreach is in complete and rare form here in the flood account.
The flood was purposed to wipe great evil from the earth and to create the seeds of a holy race which would grow into God’s elect people of Israel. The foundation of God’s elect were purified through the flood (Gen 8), God covenants with those people (Gen 8 & 9), disperses them throughout the world with the tower of Babel (Gen 11), and sets the stage for the reclaiming of his elect, beginning with Abram (Gen 12).
The Lord launches into the missions movement by establishing a covenant with all the flesh on the earth (Gen 9:17). Tim Keller once preached, “God does not have to enter into a covenant; he doesn’t have to become the Savior of the world because of its sin. He has to become the Savior of the world because of ours.” In this covenant with the people, God promises life and grace. This covenant of grace is what leads from Noah through Abram, to David, and fulfillment in Jesus. God’s covenant established here with man is in its final stages today through the reaching out to the nations (Mat 28:18-20; Acts 1:8) until every nation, tongue, and people is reached (Rev 14:6).
God is not just saying he is the Creator of the world, but he is also saying he is the Savior of the world. Through his covenant of grace Yahweh lets it be known he will save his people. God is desirous of ensuring his mercy covers the planet.
 Timothy J. Keller, The Timothy Keller Sermon Archive (New York City: Redeemer Presbyterian Church, 2013).