From John Piper, in 1988...
In order to mobilize a movement of prayer in the church and in order to sustain a will to pray in our hearts, we must think and talk about other things besides prayer. This is the key lesson I have learned in recent years.
1. We must talk first about war. Because life is war. And it is utterly impossible for people to know what prayer really is until they know that they are in a war, and until they know that the stakes of that war are infinitely higher than the stakes in the Persian Gulf or in the Reagan-Gorbachev consultations.
2. We must talk about the Sovereignty of God. Because only from this great truth can we know that we will win the war. And only then will we have hope and strength to press on in a life of prayer.
3. Then, when we have spoken first about the war we are in and next about the sovereignty of God, then we can come to what I will call the awesome place of prayer in God's purposes for the world.
Read the full article. Prayer: The Work of Missions