We read Genesis 22:15-24 in chapel today. Here's the first few verses (emphasis mine)
And the angel of the LORD called to Abraham a second time from heaven and said, "By myself I have sworn, declares the LORD, because you have done this and have not withheld your son, your only son, I will surely bless you, and I will surely multiply your offspring as the stars of heaven and as the sand that is on the seashore. And your offspring shall possess the gate of his enemies, and in your offspring shall all the nations of the earth be blessed, because you have obeyed my voice."
And I thought of 1 Corinthians 15:22-25 (again, emphasis mine)
For as in Adam all die, so also in Christ shall all be made alive. But each in his own order: Christ the firstfruits, then at his coming those who belong to Christ. Then comes the end, when he delivers the kingdom to God the Father after destroying every rule and every authority and power. For he must reign until he has put all his enemies under his feet. The last enemy to be destroyed is death.
Christ, the offspring of Abraham, will possess the gate of his enemies - he will subdue them all, such that when he returns it will be to a conquered earth (with all the nations of the earth blessed under his rule) with only death left to deal with. This 'last enemy' is then swallowed up in victory.