Prayer is the key to revival and a move of God. Even though the Holy Ghost was promised to the disciples, what did they do? In this sermon To Pray Evangelistically 2,  Persistence will pay off because we can also see that Jesus tells us to pray expectantly. We are to expect answers and miracles because of the nature of the One to whom we pray. When we have a need and we are persistent about it, God will perform the miracle for us.  God's praying people are told to give him no rest.