Matthew 6:6-8

6 But you, when you pray, enter into your inner chamber, and having shut your door, pray to your Father who is in secret, and your Father who sees in secret will reward you openly.  7 In praying, don't use vain repetitions, as the Gentiles do; for they think that they will be heard for their much speaking.  8 Therefore don't be like them, for your Father knows what things you need, before you ask him. 

Romans 8:26-28

26 In the same way, the Spirit also helps our weaknesses, for we don't know how to pray as we ought. But the Spirit himself makes intercession for us with groanings which can't be uttered.  27 He who searches the hearts knows what is on the Spirit's mind, because he makes intercession for the saints according to God.

28 We know that all things work together for good for those who love God, to those who are called according to his purpose.