For jealousy is the rage of a man: therefore he will not spare in the day of vengeance. He will not regard any ransom; neither will he rest content, though thou givest many gifts. Proverbs 6:34, 35. RRe 138.1
The heart in harmony with God is lifted above the annoyances and trials of this life. But a heart where the peace of Christ is not, is unhappy, full of discontent.... A life of selfishness is a life of evil.... Passions kept warm and fierce by Satan’s promptings, are a bitter fountain, ever sending forth bitter streams to poison the life of others.—Testimonies for the Church 5:488. RRe 138.2
Those who yield to Satan’s power gain no happiness thereby. They are never contented or at rest. They are dissatisfied, querulous and irritable, unthankful and rebellious.—Testimonies for the Church 4:207. RRe 138.3
The principle of worldlings is to get all they can of the perishable things of this life. Selfish love of gain is the ruling principle in their lives. But the purest joy is not found in riches, nor where covetousness is always craving, but where contentment reigns, and where self-sacrificing love is the ruling principle. There are thousands who are passing their lives in indulgence, and whose hearts are filled with repining. They are victims of selfishness and discontent in the vain effort to satisfy their minds with indulgence. But unhappiness is stamped upon their very countenances, and behind them is a desert, because their course is not fruitful in good works.—Testimonies for the Church 3:382. RRe 138.4