There are several places in the Word of God that simply say that under certain circumstances, God will not answer our prayers.
Because You Haven't Asked
Sometimes our prayers are not answered because we haven’t brought our request to God. James 4:2 says, “You do not have because you do not ask.” God is not going to answer your request unless you ask Him through prayer.

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Because of Unconfessed Sin
Our prayers might not be answered because of unconfessed sin. Proverbs 15:29 says, “The Lord is far from the wicked, but He hears the prayer of the righteous.” There are times as followers of Christ, our prayers go unanswered because we’re harboring unconfessed sin in our lives.
Because of Unbelief
On occasion our prayers are not answered because of our unbelief. James 1:6-8 tell us to “ask in faith, with no doubting” because the one who doubts is “double-minded.” To be double-minded is not to let the request go, but to give the request to God and then take it back. Instead of trusting God, we try to work out the solution ourselves.
Because of Unrighteous Motives
Our prayers may not be answered because of unrighteous motives. James 4:3 says, “You ask and do not receive, because you ask amiss, that you may spend it on your pleasures.” God refuses to listen to men who eagerly pursue selfish pleasures. The key to understanding this verse is the word “spend,” which means praying for something just because you want it. It has nothing to do with the will of God or the purpose of God. It’s just a selfish prayer.
Because of Unresolved Conflicts
Sometimes our prayers are not answered because of unresolved conflicts. Mark 11:25-26 say, “Whenever you stand praying, if you have anything against anyone, forgive him, that your Father in heaven may also forgive you your trespasses. But if you do not forgive, neither will your Father in heaven forgive your trespasses.” If I have offended my brother, I must go to him and make that right, or my prayers will be hindered. If my brother has offended me, I must go to him and make it right, or my prayers will be hindered. The responsibility is mine in either case to make things right with my brother, and then come to the Lord with my prayers. If you are harboring resentment, an unforgiving spirit, or anger in your heart toward another brother or sister, it may not shut down your prayer, but it will hinder it.
Because We Lack Compassion
Our prayers might not be answered because we lack compassion. Proverbs 21:13 says, “Whoever shuts his ears to the cry of the poor will also cry himself and not be heard.” The Bible says that when you harbor an uncompassionate spirit, when you don’t ask God to make you sensitive to people you can help, then it will be hard for you to have the relationship in prayer that you desire.
This article is an excerpt from Prayer the Great Adventure by Dr. David Jeremiah.