Casting down imaginations, and every high thing that exalteth itself against the knowledge of God, and bringing into captivity every thought to the obedience of Christ. 2 Corinthians 10:5.
(SD 107.1)
The Lord purifies the heart very much as we air a room. We do not close the doors and windows, and throw in some purifying substance; but we open the doors and throw wide the windows, and let heaven’s purifying atmosphere flow in.... The windows of impulse, of feeling must be opened up toward heaven, and the dust of selfishness and earthliness must be expelled. The grace of God must sweep through the chambers of the mind, the imagination must have heavenly themes for contemplation, and every element of the nature must be purified and vitalized by the Spirit of God.23
(SD 107.2)
The thoughts must be bound about, restricted, withdrawn from branching out and contemplating things that will only weaken and defile the soul. The thoughts must be pure, the meditations of the heart must be clean.... The noble powers of the mind have been given to us by the Lord, that we may employ them in contemplating heavenly things. God has made abundant provision that the soul may make continual progression in the divine life....
(SD 107.3)
We give our time and thought to the trivial and commonplace things of the world, and neglect the great interests that pertain to eternal life. The noble powers of the mind are dwarfed and enfeebled by lack of exercise on themes that are worthy of their concentration. “Whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things.” ...As we meditate upon the perfections of our divine Model, we shall desire to become wholly transformed and renewed in the image of His purity. We are called to come out and be separate from the world that we may be the sons and daughters of the Most High.24
(SD 107.4)