When you are praying, watch over yourself so that not only your outward man prays, but your inward one also. Though you be sinful beyond measure, still pray. Do not heed the devil's provocation, craftiness, and despair, but overcome and conquer his wiles. Remember the abyss of the Saviour's mercy and love to mankind. The devil will represent the Lord's fact to you as terrible and unmerciful, rejecting your prayer and repentance; but remember the Saviour's own words, full of every hope and boldness for us: `Him that cometh to Me, I will in no wise cast out'; and `Come unto Me, all ye that labour and are heavy laden' - with sins and iniquities, and wiles and calumnies of the devil - and I will give you rest.'
St. John of Kronstadt, My Life in Christ