The experience of the ages shows that the sign of the cross has great power over all a person’s actions during the entire course of his life. Therefore it is necessary to strive to root in children the habit of protecting themselves with the sign of the cross often, especially when receiving food and drink, going to bed and waking up, before departing somewhere in a vehicle, before leaving and entering any place; and they should not make the sign carelessly or according to fashion, but precisely, beginning with the forehead to the solar plexus, then to both shoulders, so that a proper cross is produced.... The sign of the cross has saved many from great dangers and afflictions.
The closet of the soul is the body; our doors are the five bodily senses. The soul enters its closet when the mind does not wander hither and thither, roaming among things and affairs of the world, but stays within, in our heart. Our senses become closed and remain closed when we do not let them be attached to external sensory things, and in this way our mind remains free from every worldly attachment, and by secret mental prayer unites with God its Father. 'And thy Father which seeth in secret shall reward thee openly,' adds the Lord. God who knows all secret things sees mental prayer and rewards it openly with great gifts. For that prayer is true and perfect which fills the soul with Divine grace and spiritual gifts.
Pray before your body takes rest on your bed... If you are tempted, make the Sign (of the Cross) on your forehead reverently… for this is a known and tested weapon against the Devil.