“There is much to fathom in Christ, for he is like an abundant mine with many recesses of treasures, so that however deep individuals may go they never reach the end or bottom but rather in every recess find new veins with new riches everywhere. On this account Saint Paul said of Christ: ‘In Christ dwell hidden all treasures and wisdom (Col. 2:3). The soul cannot enter these caverns or reach these treasures if, as we said, she does not first pass over the divine wisdom through the straits of exterior and interior suffering. For one cannot reach in this life what is attainable of the mysteries of Christ without having suffered much and without having received numerous intellectual and sensible favours from God, and without having undergone much spiritual activity; for all these favors are inferior to the wisdom of the mysteries of Christ in that they serve as preparations for coming to this wisdom”
St John of the Cross, Spiritual Canticle, 37.4.