[Wisdom's] ways are ways of pleasantness, and all her paths are peace. Proverbs 3:17. RC 153.1
This world is not all sorrow and misery. “God is love” is written upon every opening bud, upon the petals of every flower, and upon every spire of grass. Though the curse of sin has caused the earth to bring forth thorns and thistles, there are flowers upon the thistles and the thorns are hidden by roses. All things in nature testify to the tender, fatherly care of our God and to His desire to make His children happy. His prohibitions and injunctions are not intended merely to display His authority, but in all that He does He has the well-being of His children in view. He does not require them to give up anything that it would be for their best interest to retain. RC 153.2
The opinion which prevails in some classes of society, that religion is not conducive to health or to happiness in this life, is one of the most mischievous of errors. The Scripture says: “The fear of the Lord tendeth to life: and he that hath it shall abide satisfied” (Proverbs 19:23). “What man is he that desireth life, and loveth many days, that he may see good? Keep thy tongue from evil, and thy lips from speaking guile. Depart from evil, and do good; seek peace, and pursue it” (Psalm 34:12-14). The words of wisdom “are life unto those that find them, and health to all their flesh” (Proverbs 4:22). RC 153.3
True religion brings man into harmony with the laws of God, physical, mental, and moral. It teaches self-control, serenity, temperance. Religion ennobles the mind, refines the taste, and sanctifies the judgment. It makes the soul a partaker of the purity of heaven. Faith in God's love and overruling providence lightens the burdens of anxiety and care. It fills the heart with joy and contentment in the highest or the lowliest lot. Religion tends directly to promote health, to lengthen life, and to heighten our enjoyment of all its blessings. It opens to the soul a never-failing fountain of happiness. Would that all who have not chosen Christ might realize that He has something vastly better to offer them than they are seeking for themselves.... RC 153.4
There is an intimate relation between the mind and the body, and in order to reach a high standard of moral and intellectual attainment the laws that control our physical being must be heeded. To secure a strong, well-balanced character, both the mental and the physical powers must be exercised and developed. What study can be more important ... than that which treats of this wonderful organism that God has committed to us, and of the laws by which it may be preserved in health?—Patriarchs and Prophets, 600, 601. RC 153.5