The Adornment of the Spiritual Marriage, by Jan van Ruysbroeck, , at sacred-texts.com
From this zeal there spring temperance and sobriety, both inward and outward; for none can possess the right measure of sobriety save him who is greatly zealous and diligent to keep his soul and body in righteousness. Sobriety divides the higher powers from the animal powers; it saves a man from intemperance and from excess. Sobriety wishes neither to taste, nor to know, those things which are forbidden.
The incomprehensible and most high Nature of God transcends all creatures in heaven and on earth. For all that a creature can comprehend is of the creature; but God is above all creatures and within and without all creatures, and every created comprehension is too narrow to comprehend Him. But if a creature is to comprehend and to understand God, it must be caught up beyond itself into God, and comprehend God with God. Whosoever then would know and understand what God iswhich is not permittedhe would go mad. Behold, all created light is powerless to know what God is. What God is in Himself, transcends all creatures, but that God exists, is testified by nature, and by Holy Writ, and by every creature. We should believe the articles of faith, and not desire to understand them, for this is impossible as long as we are here below: such is sobriety. The mysterious and subtle teachings of Holy Writ, inspired by the Holy Ghost, should not be explained and understood in any other way than in their bearing upon the lives of Christ and His saints. Man should consider nature, and the Scriptures, and all creatures, and take from these that which profits him and nothing more. Such is sobriety of spirit.
A man should keep his senses in sobriety and should restrain the animal powers by means of the reason; so that the lusts of the flesh do not enter too far into the savouring of food and of drink; but he should eat and drink as the sick take their physic, because it is needful to support his strength, that he may serve God therewith. This is sobriety of body. He should also observe method and moderation in doing and in leaving undone, in words and in works, in silence and in speaking, in food and in drink, according to the custom of Holy Church, and after the example of the saints.
By inward and ghostly temperance and sobriety a man preserves firmness and constancy of faith, purity of intelligence, that tranquillity of reason necessary to the comprehension of truth, an impulse towards all virtues according to the will of God, peace of heart, and serenity of conscience. And herewith he possesses an enduring peace, in God and in himself.
And by temperance and sobriety of the outward bodily senses, a man often preserves the health and the soundness of his natural body, the dignity of his outward life, and a good reputation. And thus he lives in peace with himself and with his neighbours; for by his temperance and sobriety he draws to himself and pleases all men of good-will. And thus he casts out the sixth mortal sin, which is intemperance, greed or Gluttony. Of all such Christ says: Blessed are the peacemakers: for they shall be called the children of God; for they are like unto the Son, Who has made peace in every creature who desired peace. And whosoever makes peace in himself through his temperance and sobriety shall partake with Him of the inheritance of His Father; and shall possess it with Him in eternity.