If we are going to have prevailing prayer it is going to happen as a result of what the Bible speaks of in Eph. 6:18 and Jude 20 - praying "in the Holy Ghost."
The Holy Spirit guides us in this area of prayer. He is the Spirit of wisdom (Isa. 11:2). We can go to God for wisdom. We don't even need to rely on our own wisdom. We can have God's wisdom. Indeed we desperately need His wisdom. How many Christians make a total mess of their lives simply because they don't think it's important to ask God for wisdom? The Bible tells us that the Holy Spirit is the Spirit of holiness (Rom. 1:4). We can pray for God's cleansing and forgiveness. Indeed we should pray for God to forgive us, we should confess our sins to Him (that means take His position against our very own selves and sin), and forsake our sin. To be holy simply means to be clean. Are you clean? There is a cleansing available through prayer and the Holy Spirit. We can have divine comfort through prayer and the Holy Spirit. In John 14:26 Jesus calls the Holy Spirit, the "other Comforter." We as Christian's should never feel lonely since God the Holy Spirit lives in our heart. He is our Comforter, He is always there for us. What a blessing! We can go to God during our trials and ask Him for His comfort and companionship. The Holy Spirit teaches us all things and brings all things to our remembrance concerning the Lord Jesus Christ's teachings. We can rely on the Holy Spirit to be our divine teacher. What a blessing it is to be able to pray "Dear Lord, help me today as I read your Word, show me and teach me..." God is interested in instructing us every time we open His Book. In the Holy Spirit is true peace and joy (see Rom. 14:17). We can should also pray for discernment through the Holy Spirit (1 Cor. 2:10-16). We can ask God to cultivate spiritual fruit in our lives (Gal. 5:22).
So many use prayer only when they are sick and that is a crying shame. Our sinful nature is so corrupt against the things of God, that prayer is turned into a Hospital for physical ailments, rather than an action of securing spiritual blessings, and genuine communion with the Lord. Now the Lord did instruct us to pray for our "daily bread" and as well we should, but if God cares about our physical need (and He does) how much more does He care for our spiritual needs? Infinitely more.