Importance of Prayer

I've been looking at the examples of Cornelius and also the ecclesia praying for Peter in prison and have been thinking how amazing prayer is.
God heard Cornelius' prayer and him and all his household + cousins etc were all baptised and given the holy spirit and through Cornelius the door of faith was opened to the Gentiles.
James had been killed, and Peter was in prison...and it was that close 'now when Herod was about to bring him out'... but the ecclesia was praying fervently. God heard their prayer and in this instance rewarded their faith to bring about His purpose. Although I can understand Rhoda's reaction at the door...not believing it could be Peter but instead something very like him.. his angel.
Seek God, while He may be found. Continually to pray fervently: 'And this is the confidence that we have towards him, that if we ask anything according to His will he hears us'.