Luk 11:5 And he said unto them, Which of you shall have a friend, and shall go unto him at midnight, and say unto him, Friend, lend me three loaves;
Luk 11:6 For a friend of mine in his journey is come to me, and I have nothing to set before him?
Luk 11:7 And he from within shall answer and say, Trouble me not: the door is now shut, and my children are with me in bed; I cannot rise and give thee.
Luk 11:8 I say unto you, Though he will not rise and give him, because he is his friend, yet because of his importunity he will rise and give him as many as he needeth.
Luk 11:9 And I say unto you, Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you.
Luk 11:10 For every one that asketh receiveth; and he that seeketh findeth; and to him that knocketh it shall be opened.
Luk 11:11 If a son shall ask bread of any of you that is a father, will he give him a stone? or if he ask a fish, will he for a fish give him a serpent?

Luk 18:1 And he spake a parable unto them to this end, that men ought always to pray, and not to faint;
Luk 18:2 Saying, There was in a city a judge, which feared not God, neither regarded man:
Luk 18:3 And there was a widow in that city; and she came unto him, saying, Avenge me of mine adversary.
Luk 18:4 And he would not for a while: but afterward he said within himself, Though I fear not God, nor regard man;
Luk 18:5 Yet because this widow troubleth me, I will avenge her, lest by her continual coming she weary me.
Luk 18:6 And the Lord said, Hear what the unjust judge saith.
Luk 18:7 And shall not God avenge his own elect, which cry day and night unto him, though he bear long with them?
Luk 18:8 I tell you that he will avenge them speedily. Nevertheless when the Son of man cometh, shall he find faith on the earth?

Keep praying and believing till the answer to prayer comes. Lots of times God's just because God doesn't answer right away, doesn't mean the answer is no, it may just mean wait, and sometimes it's just our prayer being tested.

As in the parable of the widow who kept pestering the judge, Jesus is saying we need to continue praying and not give up. And if we ask for bread, will he give us a stone?

Heb 11:6 But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.

Diligence:
-- Earnest and persistent application to an undertaking; steady effort; assiduity.
-- Attentive care; heedfulness.