The Intense Prayer of a Christ Follower is powerful and effective!

James 5:13-18 (HCSB)
13 Is anyone among you suffering? He should pray. Is anyone cheerful? He should sing praises.
14 Is anyone among you sick? He should call for the elders of the church, and they should pray over him after anointing him with olive oil in the name of the Lord.
15 The prayer of faith will save the sick person, and the Lord will raise him up; and if he has committed sins, he will be forgiven.
16 Therefore, confess your sins to one another and pray for one another, so that you may be healed. The intense prayer of the righteous is very powerful.
17 Elijah was a man with a nature like ours; yet he prayed earnestly that it would not rain, and for three years and six months it did not rain on the land.
18 Then he prayed again, and the sky gave rain and the land produced its fruit.

1 Kings 17:1 (HCSB)
1 Now Elijah the Tishbite, from the Gilead settlers, said to Ahab, “As the Lord God of Israel lives, I stand before Him, and there will be no dew or rain during these years except by my command!”

1 Kings 18:41-46 (HCSB)
41 Elijah said to Ahab, “Go up, eat and drink, for there is the sound of a rainstorm.”
42 So Ahab went to eat and drink, but Elijah went up to the summit of Carmel. He bowed down to the ground and put his face between his knees.
43 Then he said to his servant, “Go up and look toward the sea.” So he went up, looked, and said, “There’s nothing.” Seven times Elijah said, “Go back.”
44 On the seventh time, he reported, “There’s a cloud as small as a man’s hand coming from the sea.” Then Elijah said, “Go and tell Ahab, ‘Get [your chariot] ready and go down so the rain doesn’t stop you.’ ”
45 In a little while, the sky grew dark with clouds and wind, and there was a downpour. So Ahab got in [his chariot] and went to Jezreel.
46 The power of the Lord was on Elijah, and he tucked his mantle under his belt and ran ahead of Ahab to the entrance of Jezreel.