“Seeing that the Scripture saith, God has made all for His own glory (Isa. 43.7), surely His creatures ought to conform themselves, as much as they can, to His will. In Him should all our affections center, so that in all things we should seek only to do His will, not to please ourselves. And real happiness will come, not in gratifying our desires or in gaining transient pleasures, but in accomplishing God’s will for us: even as we pray every day: ‘Thy will be done in earth as it is in heaven’ (Matt. 6.10). O chaste and holy love! O sweet and gracious affection! O pure and cleansed purpose, thoroughly washed and purged from any admixture of selfishness, and sweetened by contact with the divine will! To reach this state is to become deified. As a drop of water poured into wine loses itself, and takes the color and savor of wine; or as a bar of iron, heated red-hot, becomes like fire itself, forgetting its own nature; or as the air, radiant with sun-beams, seems not so much to be illuminated as to be light itself; so in the saints all human affections melt away by some unspeakable transmutation into the will of God. For how could God be all in all, if anything merely human remained in man? The substance will endure, but in another beauty, a higher power, a greater glory. When will that be? Who will see, who possess it? ‘When shall I come to appear before the presence of God?’ (Ps. 42.2). ‘My heart hath talked of Thee, Seek ye My face: Thy face, Lord, will I seek’ (Ps. 27.8). Lord, thinkest Thou that I, even I shall see Thy holy temple?”
– Bernard of Clairvaux (1090-1153), On Loving God, Ch. 10.
* While Bernard here uses the term “deified” which may put many of us off, I suggest reading it in the sense of “being conformed to the image of God.“