What does it mean that there is a plan of God for the ages?
God's plan for the ages is His pre-creation blueprint for all history: before anything was created, the triune God put everything in motion and already had it all planned. It covers the whole picture from Genesis to Revelation, including resurrection at the end of the age, while men and nations operate under the free will God gave them.
Les explains that in 1 Corinthians 15 Paul shifts gears from discussing Christ's resurrection to the end of the age, bringing resurrection into the whole picture of God's plan of the ages. Les teaches the Bible from Genesis to Revelation as God's plan for the ages. When he speaks of God's plan for the ages, he means that before anything was created, the triune God put everything in motion and already had it blueprinted. One amazing and hard-to-comprehend point is that God from the beginning gave men and nations their free will; they have operated under it, with governments making decisions, invading other nations, and raising navies and producing air forces. The context ends mid-sentence at “But yet from the beginning of time until,” so it does not state the next conclusion.