Luke 18:1  "Then Jesus told his disciples a parable to show them that they should always pray and not give up."  We ought always to be in the state of prayer.

Matthew 6:5-15  "And when you pray, you shall not be as the hypocrites are: for they love to pray standing in the synagogues and in the corners of the streets, that they may appear of men. Verily I say to you, They have their reward.  But you, when you pray, enter into your closet, and when you have shut your door, pray to your Father which is in secret; and your Father Who sees in secret shall reward you openly.  But when you pray, use not vain repetitions, as the heathen do: for they think that they shall be heard for their much speaking.  Be not you therefore like to them: for your Father knows what things you have need of, before you ask him.  After this manner therefore pray you: Our Father Who is in heaven, Consecrated be your name.  your kingdom come. Your will be done in Earth, as it is in heaven.  Give us this day our daily bread.  And forgive us our debts, as we forgive our debtors.  And lead us not into temptation, but deliver us from evil: For yours is the kingdom, and the power, and the glory, into the eon. Amen.  For if you forgive men their trespasses, your heavenly Father will also forgive you:  But if you forgive not men their trespasses, neither will your Father forgive your trespasses.  Moreover when you fast, be not, as the hypocrites, of a sad countenance: for they disfigure their faces, that they may appear to men to fast. Verily I say to you, They have their reward."

Fasting and Prayer:

Matthew 6:16  "But you, when you fast, anoint your head, and wash your face;  That you appear not to men to fast, but to your Father which is in secret: and your Father, Who sees in secret, shall reward you openly. 

Praying God's prayer:

This is an interesting quote. "Whatever is not of faith is sin." That means that a prayer that is not of faith is sin. Since faith is the supernatural faith of God that comes with God speaks to those who are willing to listen and obey, a righteous prayer is one that God inspired. "Faith comes by hearing and hearing comes by the utterance of God." We ought to pray everything that God tells us to pray and nothing else. One move Scripture that relates, "through [our Lord Jesus Christ] we have gained access by faith into this grace in which we now stand." We now stand in this grace, faith is the door of access into this grace. In other words, faith gives access to grace and grace prays God's prayers through us. In this way, we pray the will of God because He was the One who led us to pray and also prayed the prayer through us.

(some caveats about hearing God's Voice)