"Prayer is a great blessing" - St. Teresa of Avila

How great is the good which God works in a soul when He gives it a disposition to pray in earnest, though it may not be so well prepared as it ought to be.
If  that soul perseveres in spite of sins, temptations and relapses, brought about in a thousand ways by Satan, our Lord will bring it at last – I am certain of it – to the harbour of salvation, as He has brought me myself. 
May His Majesty grant I may never go back and be lost!
He who gives himself to prayer is in possession of a great blessing, of which many saintly men have written - I am speaking of mental prayer - glory be to God for it! 
Let him never cease from prayer who has once begun it, be his life ever so wicked; for prayer is the way to amend it, and without prayer such amendment will be much more difficult.
As to him who has not begun to pray, I implore him by the love of our Lord not to deprive himself of so great a good.

(Sr. Mary ocd (ed) ,Living Water, Daily Readings with St. Teresa of Avila, 1)