Know the difference between vain repetition and faith repetition. If someone does not pray to the Father through Jesus Christ, or if he does not pray with faith, then any repetition is meaningless. Repeating a prayer like it is a mantra or an incantation does not make it more likely to be answered. If you pray in faith, you can pray it again. If you pray in unbelief, even the first time is futile. The Bible says do not think that you will get anything from the Lord.
There are two legitimate types of repetition.
First, there is the prayer of dedication. Before Jesus was arrested, he prayed the same thing several times. He was not really asking for anything. He knew what he came to do and what was about to happen. He was preparing himself for a time of difficult ministry. If we wish, we may also include praise, worship, and thanksgiving in this kind of prayer. You ought to say, “Praise the Lord, for he is good, and his mercy endures forever.” You may say that as often as you think of it. It is not vain repetition as long as you mean it. In this type of prayer, you embrace the will of God as you pray (Matthew 26:39, 42).
Second, there is the prayer of petition. Jesus told a story about a widow, who persisted with an unjust judge until he granted her the justice that she demanded. The story does not intend to say that God is like an unjust judge, but the point is that if even an unjust person would surrender to a widow’s persistence, God is much more ready to answer our prayers when we come to him in an unwavering faith. In this type of prayer, you discover the will of God before you pray (1 John 5:14-15).
Christians often place every prayer under the first category. They make petitions using the principles of dedication. This is why they are weaklings and failures. Stop playing humble when God has already promised you victory and commanded you to move forward in faith (Exodus 14:15)!
The main issue in prayer is faith, not techniques or mechanics. Most prayers come from unbelief, and most repeated prayers come from repeated unbelief. If you have faith, you can pray once and receive, or you can ask again. If prayer is more than mere psychological release, and if you truly expect to receive what you ask, then you can press hard for something until you receive it, or keep pushing for further progress until you are satisfied.
Any Christian can improve if he will stop making excuses and correct his theology, and start praying and speaking in faith. This will often mean disowning his teachers and traditions, even condemning them. He will have to decide if Christ is worth more to him than these things.