Then I commended mirth, because a man hath no better thing under the sun, than to eat, and to drink, and to be merry: for that shall abide with him of his labour the days of his life, which God giveth him under the sun. Ecclesiastes 8:15. RRe 142.1
Some preserve a cold, chilling reserve, an iron dignity, that repels those who are brought within their influence. This spirit is contagious; it creates an atmosphere that is withering to good impulses and good resolves; it chokes the natural current of human sympathy, cordiality, and love; and under its influence people become constrained, and their social and generous attributes are destroyed for want of exercise.—Testimonies for the Church 4:64. RRe 142.2
You have a duty to perform, which is to make yourself cheerful, and to cultivate unselfishness in your feelings until it will be your greatest pleasure to make all around you happy.... You need to soften your hearts and be imbued with the Spirit of Christ, that you may, while living in an atmosphere of cheerfulness and benevolence, help those about you to be healthy and happy also. You have imagined that cheerfulness was not in accordance with the religion of Christ. This is a mistake. We may have true Christian dignity, and at the same time be cheerful and pleasant in our deportment. Cheerfulness without levity is one of the Christian graces.—Testimonies for the Church 4:62. RRe 142.3