If a man does not carry out the will and law of God ‘in his inward parts’, that is, in his heart, he will not be able to carry them out easily in the outward sphere of the senses either. The careless and unwatchful man will say to God: ‘I do not want to know Thy ways’ (Job 21:14, LXX), obviously because he lacks divine illumination. But he who participates in that light will be confident and steadfast in matters that concern God.
Many of our thoughts come from demonic provocation, and from these derive our evil outward actions. If with the help of Jesus we instantly quell the thought, we will avoid its corresponding outward action. We will enrich ourselves with the sweetness of divine knowledge and so will find God, who is everywhere. Holding the mirror of the intellect firmly towards God, we will be illumined constantly as pure glass is by the sun. Then the intellect, having reached the term of its desires, will in Him cease from all other contemplation.
The more closely attentive you are to your mind, the greater the longing with which you will pray to Jesus; and the more carelessly you examine your mind, the further you will separate yourself from Him. Just as close attentiveness brilliantly illumines the mind, so the lapse from watchfulness and from the sweet invocation of Jesus will darken it completely.