The power of prayer

From JC Ryle:

Prayer obtains fresh and continued out-pouring of the Spirit. He alone begins the work of grace in a man's heart. He alone can carry it forward and make it prosper. But the good Spirit loves to be entreated. And those who ask most, will always have most of His influence.
 
Prayer is the surest remedy against the devil and besetting sins. That sin will never stand firm which is heartily prayed against. That devil will never long keep dominion over us which we beseech the Lord to cast forth. But, then, we must spread out all our case before our heavenly Physician, if He is to give us daily re- lief. We must drag our indwelling devils to the feet of Christ, and cry to Him to send them back to the pit.