Matthew 6:8: Be not ye therefore like unto them: for your Father knoweth what things ye have need of, before ye ask him.
God wants us to know that He knows everything even before we ask Him, but He still wants us to pray to Him and make known our supplications. God does not want us to blabber something or repeat some vain things over and over again when we speak to Him. He desires that we make known our requests directly to Him and be specific about what we actually need.
Many saints in the Bible often prayed and asked God what they needed. In the New Testament, the blind beggar cried out to Jesus to have mercy upon Him. Though Jesus knew he needed to see, He asked him what he wanted. He got a new pair of eyes and was able to see. When God does not answer our prayers, it does not mean that He has not heard them. It only means that He will answer it in His own time, nevertheless keep asking Him. He knows what we need but does not always give us what we need. He will give us what He thinks is the best. So, do not pray like people who do not know who the real God is. Stop mumbling and muttering in prayer. Keep your traditional mindset of prayer aside and come to God like you believe that He will do what you ask of Him.
Even though He knows what we need of Him, He wants us to ask Him because He wants to listen to your voice of cry for an answer. Therefore, release faith when you ask God to do something for you. He loves to listen from people who have faith.