Hebrews 11:6 But without faith it is impossible to please him: for he that comes to God must believe that he is, and that he is a rewarder of them that diligently seek him.
The only reason for unanswered prayer to a Christian is “unbelief” (Matt. 17:17-21; Jas. 1:5-8; Heb. 11:6). Unbelief is caused by wrong teaching (Rom. 10:17). The promises are unlimited (Ps. 34:9-10; 84:11; 91:1-12; Matt. 17:20; 21:22; Mark 9:23; 11:22-24; John 15:7, 16), so if there is a limitation in answer there is a limitation of faith, not of God’s will or power.
There are many reasons given for unanswered prayer in Scripture: Refusing to listen to the truth (Pro. 28:9). Refusing to humble self (2Chron. 7:14). Forsaking God (2Chron. 15:2). Provoking God (Deut. 3:26). Hardheartedness (Zech. 7:12-13). Lack of charity (Pro. 21:13). Regarding iniquity in the heart (Ps. 66:18). Wrong motives (Jas. 4:3). Dishonour of companion (1Pet. 3:7). Unbelief (Matt. 17:20-21; 21:22). Sin (Jas. 4:1-5; John 9:31; Isa. 59:2). Parading prayer life (Matt. 6:5). Vain repetitions (Matt. 6:7). Unforgiveness (Matt. 6:14-15; Mark 11:25-26). Hypocrisy (Luke 18:9-14). Being discouraged (Luke 18:1-8). Worry and anxiety (Php. 4:6). Doubting – double-mindedness (Jas. 1:5-8).
From James 4 another twelve reasons are given for unanswered prayer: Lusts (Jas. 4:1, 2, 3, 5; John 8:44); murders, covetousness, fighting and war, asking amiss to satisfy lusts, adultery, friendship, pride, rebellion against God, backsliding and sin, double-mindedness or doubt and the misuse of the tongue. This passage should never be taken by the Christian as an excuse for unanswered prayer. By so doing he automatically classes himself as lustful, murderous, covetous, adulterous, worldly, proud, sinful, and blasphemous. No man can ask amiss if he is in Christ and asks according to the promises (John 15:7; Mark 11:22-24; Heb. 11:6; Jas. 1:5-8). The reason Christian prayers are not answered is because of their unbelief.

