Father Girardey further explains why mental prayer is necessary to live a virtuous life.
“In order to know ourselves, we have also to know our relation, our duties towards God and what is required to fulfil them. . . . We should know what He has done for us, how much He loves us, how we absolutely depend on Him for all we have and all we are, the fearful malice of grievous sin, the frightful punishment it deserves, and be well penetrated with the eternal truths, our final destiny and the means of securing it, death, judgment, the eternal rewards and punishments. . . . These all-important matters, the truths of faith are seen, not with our corporal eyes, but with those of our mind and can be properly contemplated and examined and become our guide only by means of mental prayer, by means of practical meditations.”
“How can we know God and His infinite perfections and His boundless love and benefits towards us, if we do not seriously reflect on them? How can we appreciate the importance of salvation, the malice of sin, the value of divine grace, the necessity of prayer to fulfil our duties, if we fail to reflect seriously and practically on these truths?” He who fails to devote time to such serious reflection has reason to say: “My heart is withered, because I forgot to eat my bread” (Ps 101:5).
“What virtues can we acquire in this way? Faith? But ardent faith requires the nourishment of both reflection and petitions. Humility? But how can we be come humble without studying ourselves and our perverse inclinations and our helplessness? And if we do not truly know ourselves, how can we correct our defects? And moreover, without serious practical reflection our charity, our patience, our obedience will lack the supernatural sap which raises our works to God, and our virtues will be only apparent rather than real and solid, merely natural instead of supernatural, as they should be, in order to please God and deserve heavenly reward and secure our salvation. Hence Gerson, celebrated for both his great learning and piety, does not hesitate to say that ‘he who does not meditate, that is, does not seriously and practically reflect on the matters that concern his salvation, cannot, without a miracle, lead a truly Christian life.'”
Quotations from Ferreol Girardey, Prayer: Its Necessity, Its Power, Its Conditions (St. Louis: B. Herder, 1916).