Have you even known a few people that when they pray, you know they have been in touch with God.

I. .Indifference........ Proverbs 1:24-30

Become indifferent to God - to His word - to the leadership of the Spirit and expect to have a real prayer life -- prayer life where God hears because our hearts are not only right but they are sensitive to the things of God.

II. Outright Disobedience.......... Deuteronomy 1:41-45

There is disobedience, and it is disobedience, that is done so out of ignorance - or perhaps a slip - or in a weak moment.
You didn't set your mind to be disobedient. But, there are those times, and everyone has them, when you rebel against God's guidance. That is outright disobedience. It will stunt prayer every time.

III.Stubbornness ..............Zechariah 7:12,13

Outright disobedience and stubbornness often go hand in hand. Refusing to call black, black, refusing to heed the word, to heed the warning. Trying going to God with a stubborn heart and see what happens.

IV.Double-Minded or Unstable .............James 1:6-7

Walking the fence with kill your prayer life. Two faced and flip-flopping will defuse any prayer.

V. Selfish/Self-centeredness .................James 4:3

Nothing cuts the wings of prayer like selfishness. Motives are as important to God as actions. You may have a great devotional life but if you entering into your devotions with the idea that "God must bless me because...", then you wasting  your time. By the way, you are wasting your time, not God's time. He isn't listening.

VI. Iniquities (Sin).............. Isaiah 59:2

Iniquity carries this idea of 'lawlessness'.  It has this idea of being a law within oneself and not being subject to other laws.  It's wild, uncontrollable.

VII. Lack of Mercy ............Proverbs 21:13

Let me share with you what I call the Measuring Priniciple.

Matthew 7:22  ... For with what judgment ye judge, ye shall be judged: and with what measure ye mete, it shall be measured to you again.

Mark 4:24 And he said unto them, Take heed what ye hear: with what measure ye mete, it shall be measured to you: and unto you that hear shall more be given.

Luke 6:38 Give, and it shall be given unto you; good measure, pressed down, and shaken together, and running over, shall men give into your bosom. For with the same measure that ye mete withal it shall be measured to you again.

Lack in hearing and giving mercy and - You got it - Don't expect your cries for mercy to be heard.