John of Damascus

Obtain the same thing for yourself and strive to advance toward it; for it is able to raise you from earth to heaven. You will not advance in it without preparation or [solely] by chance. First cleanse your soul of every passion and wipe it as clean of every evil as a newly cleansed mirror. Remove far from you every recollection of wrong and anger, which most of all prevents our daily prayers from reaching God. Also remove from your heart the offenses of everyone who has ever sinned against you. Giving wings to your prayer with mercy and compassion for the poor, approach God with fervent tears. Praying in this way you will be able to say with the blessed David, who, although he was king and burdened with countless cares, cleansed his soul of all passions: "I hated and abhorred iniquity, but I loved your law. Seven times a day I praised you because of the judgments of your righteousness." My soul kept your testimonies and I loved them very much. Let my prayer draw near to you, Lord; enable me to understand your word.