"The sovereignty of God in grace gives us our only hope of success in evangelism." -(J.I. Packer from "Evangelism & the Sovereignty of God")
Students from time to time will ask me concerning God's sovereignty in salvation, "why pray for the salvation of people who are already elected for salvation?" Its a good question, but as Packer points out, when we pray for God to reveal Himself to others and to save the lost, we show that we not only believe that He's sovereign in control of their salvation, but we also show our desire for Him to be so.