The voice of Jesus.
My Child, with all watchfulness, keep thy heart safe for Me: for from it proceeds either life or death.
The greatest and most pleasing gift thou canst offer, is to present thy whole heart irrevocably to Me; and thou canst have no better, nor more wholesome employment, than, to preserve thy heart faithfully for Me.
The self-collected man keeps watch over all the avenues of the heart; Me, his God and Saviour, he entertains within himself; with Me he deals generously, with Me he converses familiarly.
Everywhere self-possessed, he peacefully enjoys the Beloved of his soul, and is ever saved from wearisomeness, and from numberless faults. Whilst inwardly recollected, he makes progress in virtue; and, in spite of every obstacle, he hastens on to perfection.
Observe carefully, with what objects thy heart busies itself; by what it is moved, towards what it tends. Turn thyself wholly to interior things; and, intent on these, preserve inward peace, and rejoice in My presence.
The voice of the Disciple.
Grant me, I beseech Thee, Lord Jesus, an inward spirit, that I may keep my heart for Thee, that I may watch over its employments.
For I find it ever busy but, by reason of my neglectfulness, it heeds neither place, nor time, nor objects.
It is never at rest: when it escapes from one object, it is entangled in another. It is excited by curiosity, it is allured by cupidity, it is misled by vanity, it is defiled by pleasure, it is wasted by sadness, it is tortured by envy, it is disturbed by love and hatred, it is worried by its own misery, and by worrying itself it is broken down.
Thus is my heart busied, thus is it defiled, when , watch not over it, or when I am careless about it.
Imitation of the Sacred Heart of Jesus, Chapter XXI