True prayer is an approach of the soul by the Spirit of God to the throne of God.
– Charles Spurgeon

Prayer is a sincere, sensible, affectionate pouring out of the heart or soul to God through Christ, in the strength and assistance of the Holy Spirit, for such things as God hath promised, or according to the Word, for the good of the church, with submission, in Faith, to the will of God
– John Bunyan

 The Spirit, as an enlightening Spirit, teaches us what to pray for, as a sanctifying Spirit works and excites praying graces, as a comforting Spirit silences our fears, and helps us over all our discouragements.  The Holy Spirit is the spring of all our desires and breathings toward God.
– Matthew Henry

My lack of fervor is no reason to rein in my prayers.  As I pray so weakly, the Holy Spirit strongly pleads for me with groans deeper than I can express to touch the heart of the Father.  And the Father, who sent his Son and his Spirit to be our advocates, loves to listen – and respond.
– Bryan Chapell

The fervor of the Holy Spirit makes my prayers dear to the Father and the power of the Holy Spirit conforms my prayers to his design.  These truths are amazing and comforting.  Because the Spirit works through my prayers to do his will, I do not have to know all the answers or emote just the right feeling for God to use me.  I do not have to say everything right or do everything right to have all things turn out right.  The Spirit takes these burdens from me.  The Holy Spirit uses fallible prayers offered in faith to accomplish God’s perfect will.
– Bryan Chapell