Here are some wise words from St Augustine on prayer, written to a Roman noble woman called Anicia Faltonia Proba, who was also a friend of John Chrysostom.
In order to obtainin this true blessed life, He who is Himself the True Blessed Life has taught us to pray. We do not have to pray with many words, as if our being heard depended upon the fluency with which we express ourselves, because we are praying to One who, as the Lord tells us, knows what things we have need of before we ask Him (Matthew 6.7-8). It may seem surprising that, although He has forbidden much speaking, He who knows what we need before we ask Him has exhorted us to ‘always to pray and not to faint’… giving us the example of a widow, who, desiring to have justice done against her adversary, by her persevering entreaties persuaded an unjust judge to listen to her. He was not moved because of justice or mercy, but overcome by her tiresome persistence. In this he teaches us how much more certainly the Lord God (who is merciful and just), hears our prayers to him… To teach us the same thing, Jesus also said ‘ask, and you shall receive; seek, and you shall find; knock, and it shall be opened unto you: for every one that asks receives; and he that seeks finds; and to him that knocks it shall be opened.’… Why this should be necessary, since God knows what we need before we ask Him, might perplex us. But we should understand that the Lord our God wants us to ask not to be informed of our wishes (for nothing can be hidden from Him), but that by our asking, desire might deepen in us, and through our desire God prepares us to receive what He wishes to bestow. His gifts are very great, but our capacity to receive them is small and meagre. That is why Scripture says, ‘open your hearts and do not share the lot of unbelievers.’ For, in proportion to the simplicity of our faith, the firmness of our hope, and the ardour of our desire, will we more fully receive that which is immensely great; which eye has not seen, for it is not colour; which the ear has not heard, for it is not sound; and which has not entered into the heart of man, for the heart of man must enter it.
Letter 130.VIII.xv, xvi, xvii