In educating, it is extremely dangerous to only develop the understanding and intellect, and not pay attention to the heart. We must, above all pay attention to the heart, for the heart is life, but life corrupted by sin. It is necessary to purify this source of life, to kindle in it the pure flame of life, so that it should burn and not be extinguished; and should direct all the thoughts, desires, and tendencies of the man through all his life. Society is corrupted precisely through the want of Christian education. It is time that Christians should understand the Lord, should understand what He requires of us; namely, a pure heart. Blessed are the pure in heart (Matt. 5:8). Listen to His sweetest voice in the Gospel. The true life of our heart is Christ (Christ liveth in me (Gal. 2:20)). Let all of you learn wisdom of the Apostle. This should be our common problem: to bring Christ to dwell in our hearts through faith.–St. John of Kronstadt 

Wisdom is good with an inheritance: and by it there is profit to them that see the sun. For wisdom is a defense, and money is a defense: but the excellency of knowledge is, that wisdom giveth life to them that have it. (Eccl. 7:11-12)