Revivals are a means of bringing in more of Christ's sheep.
Our passage reminds us that Jesus had a work to do when He came into the world; He was sent specifically to give Himself as a guilt offering for the sins of His people. It also reminds us that the Father promised Him a reward for this work: the very people for whom He would lay down His life.
Revival accelerates the subduing of Jesus' enemies - either in joyful submission or through fear of His being. This is something that must happen before He returns. This is another reason why revival is so important.
Jesus is King today, and one day every knee will bow to Him. This won't come without the Word and Spirit, and so the people of God must evangelize and pray.
Jesus tells us what would happen after He departed this world for glory. He would send the Holy Spirit, and the Spirit would work in different ways in the hearts of those who know God and those who do not.
Peter and John are commanded not to teach any longer in the name of Jesus but they refuse. Returning to the disciples, they pray that they may speak the Word of God with boldness. The place is shaken, they are filled with the Holy Spirit and enabled to do that very thing.
Revival is sovereignly in God's hands; He chose those whom He will revive before the foundation of the world.
While God will work all things according to His will in order to bring revival in His time, His sovereignty does not negate our responsibility to seek the lost.revival, God's sovereignty, man's responsibility, evangelism