Wisdom from Elder Leonid of Optina
Disciple: Is mental prayer granted to everyone?
Elder Leonid: Whomever the Lord visits with grievous trial, with sorrow or with the deprivation of a beloved neighbour: such a person will involuntarily pray with his whole heat, with all his thoughts and with all his mind. Consequently the wellspring of prayer is in everyone; but it is tapped either by gradually delving deeper into oneself in accordance with the teachings of the Fathers, or instantaneously, by God’s drill.
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Wisdom from Elder Leonid of Optina