The key to power is the consistence in prayers. It is not the words of praying or how to do it but it is the power not to give up in prayers. Jesus told us not to lose heart when the answer to prayer is impending. Don't give up, keep praying and don't lose heart! God will answer our prayers according to His time, not our set time for God to answer.
Our persistence in prayer demonstrates the depth of our needs. We place before the Lord our genuine needs and continue to ask for them until we get the peace of the mind. Real prayer always begins with God because we are dependent upon God. The more we recognize our dependence on God the more we seek God through prayer. Dependence upon God requires a desire to pray because we need God and God alone satisfies our needs. Prayer itself is God's gift to us that enables us to communicate to God through prayers. In other words we are invited to talk to and to listen to God.
The parable of the widow and the unrighteous judge depicts the victim as a widow in contrast to the powerful judge who is neither fear of God nor respects for people. There are not many things that made him move to have affections for the widow. In this view the widow had very little hope. The story revealed that the widow somehow persisted and that made the judge gave her justice. Persistence was the key power for her to bargain. Persistent pressure was the key to make the unrighteous judge to give her what she asked for.
Like the widow when we encounter problems that seem enormous failure or loss are eminent. Perpetual prayer is the key to the mercy of God. Jesus told us not to stop praying but continuous praying, crying out to God whom we cannot see but trusting in God's mercy and compassion. We strongly believe that God will come to our rescue. Jesus affirms to us that we know what is good to give to our children.
How much more will the heavenly Father give the Holy Spirit to those who ask Him 11:13.
And will not God vindicate his elect, who cry to him day and night? Will he delay long over them? I tell you, he will vindicate them speedily. Luke 18:6
The parable is about the need to pray always and to not lose heart because the delays in prayers are harmful to us. It will change us, make us stop praying. Persistence in prayers is not for God but for our own benefits. Prayers transform our lives and make the connection our lives to God's love. Through prayers God will transforms our heart and that makes us to care about things the same way as Jesus did.
True prayer is faith expression in words and in listening. To pray is to believe what you ask will be granted. Prayer is giving thanks to God not complaining about the state of life that we are in. Living relationships require words and interchange, utter the feelings of the heart in its deepest moods. That is the true expression of faith.