Luke 18:1 (AMPC), “Also [Jesus] told them a parable to the effect that they ought always to pray and not to-turn coward (faint, lose heart, and give up).”
 

God is more concerned about our prayer persistence than our prayer posture. Jesus told a parable, in Luke 18, about a widow who’s persistence in receiving justice, caused a reluctant judge to move on her behalf. At the end of the parable, Jesus declared that He will not delay to defend those who cry out to Him for help, when they persistently call upon Him, refusing to lose heart and draw back in unbelief. He said, “I tell you, He will defend and protect and avenge them speedily. However, when the Son of Man comes, will He find [persistence in] faith on the earth?” (Luke 18:8). When we are standing in faith concerning a promise from God’s Word, we are not to become discouraged when we don’t see the answer right away. In the parable of the widow and the judge, scripture tells us that the judge had no fear of God and had little respect or regard for people (v:4). This unjust judge did not believe in a higher moral authority, so he literally regarded himself as a law unto himself. The more the widow appealed to the judge to rule for her cause, the more he dismissed her. And yet, she didn’t for a moment let up on her persistence until he became altogether weary of her insistence and gave into her request. Jesus said the point to this parable is that it’s a parable of contrast. While the judge is unjust, Jesus is not. While the widow is poor and desperate, we who are in Christ are not. Yet, if such an unjust judge in the parable, finally relents and is compelled to help the widow he has no regard for - how much more will our good and generous Heavenly Father, Who delights to take care of us, make sure we can trust Him to move on our behalf. When we remain persistent in communicating our needs to Him, we can trust Him to honour His Word concerning us! When His Word has promised you something, remain persistent in prayer.  Always make your requests known to Him and expect His generous and attentive response!