If, as St Paul says, Christ dwells in our hearts through faith (Ephesians 3:17), and all the treasures of wisdom and spiritual knowledge are hidden in Him (Colossians 2:3), then all the treasures of wisdom and spiritual knowledge are hidden in our hearts. They are revealed to the heart in proportion to our purification by means of the commandments….
This is the treasure hidden in the field of your heart (Matthew 13:44), which you have not yet found because of your laziness. Had you found it, you would have sold everything and bought that field. But now you have abandoned that field and give all your attention to the land nearby, where there is nothing but thorns and thistles….
It is for this reason that the Savior says, ‘Blessed are the pure in heart, for they shall see God’ (Matthew 5:8): for He is hidden in the hearts of those who believe in Him. They shall see Him and the riches that are in Him when they have purified themselves through love and self-control; and the greater their purity, the more they will see.
~St Maximos the Confessor