Luke 18:1-8 (KJV)

1 And he spake a parable unto them to this end, that men ought always to pray, and not to faint;

2 Saying, There was in a city a judge, which feared not God, neither regarded man:

3 And there was a widow in that city; and she came unto him, saying, Avenge me of mine adversary.

4 And he would not for a while: but afterward he said within himself, Though I fear not God, nor regard man;

5 Yet because this widow troubleth me, I will avenge her, lest by her continual coming she weary me.

6 And the Lord said, Hear what the unjust judge saith.

7 And shall not God avenge his own elect, which cry day and night unto him, though he bear long with them?

8 I tell you that he will avenge them speedily. Nevertheless when the Son of man cometh, shall he find faith on the earth?

In this parable Jesus encourages us to pray always and not loose heart when we don’t see the answer yet. That reminds me of 1 Thessalonians 5:17 (KJV) Pray without ceasing., and 1 John 5:14 (KJV) And this is the confidence that we have in him, that, if we ask any thing according to his will, he heareth us: James 4:3 (KJV) Ye ask, and receive not, because ye ask amiss, that ye may consume it upon your lusts. James 1:6 (KJV) But let him ask in faith, nothing wavering. For he that wavereth is like a wave of the sea driven with the wind and tossed. Hebrews 11:6 (KJV) 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.
When we pray as Jesus taught us in Matthew 6:5-15 we come to Him in faith, give glory to Him, humble ourself submit ourself to His will and ask accordingly.
Have a read of the parable following this one Luke 18:9-14 tells us that we should not trust in ourself but in the Lord and that we should come to Him in humility acknowledging our inadequacy. Let’s be diligent when we pray not give up asking, seeking and knocking in faith.
Luke 11:9-10 (KJV)

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.

10 For every one that asketh receiveth; and he that seeketh findeth; and to him that knocketh it shall be opened.