Matthew 6:16
Moreover when ye fast, be not, as the hypocrites, of a sad countenance: for they disfigure their faces, that they may appear unto men to fast. Verily I say unto you, They have their reward. Moreover when ye fast, be not, as the hypocrites, of a sad countenance: for they disfigure their faces, that they may appear unto men to fast. Verily I say unto you, They have their reward.
Jesus spoke these words in the Sermon on the Mount, given especially to His disciples while the multitude also listened and could hear. As part of that sermon it teaches the conditions of entrance into God's kingdom and its foundational principles, correcting false ideas about the kingdom. As part of that sermon it teaches the principles of a kingdom of divine grace rather than promising earthly glory or political deliverance. As part of that sermon it stands against the doctrines and practices of the self-righteous scribes and Pharisees and challenges their human traditions presented as God's commandments, without further elaboration on fasting. As part of that sermon it presents the law of God as reaching beyond outward conduct to the principles of the heart.
It belongs to the pure gospel given upon the Mount that explains God's holy law and sets the holy standard of character. As part of the instruction of the sixth chapter, it teaches contentment and submission of the will to the Holy Spirit rather than striving for wealth, position, or recognition. It forbids fasting with a sad countenance and disfigured face to attract notice and display piety, and such hypocritical fasting done to win human praise earns only the earthly human approval sought and not a lasting reward. The same principle applies to public displays of virtue and religious honor sought for human praise. It bears on fasting imposed on oneself as a religious work, for such fasting with prayer can harm health, and God has not required it.
Pharisaical righteousness of that kind comes from self-reliance rather than from Christ, while salvation rests on the merits of the crucified and risen Saviour and not on works intended to earn heaven. Its holy standard requires loving God with the whole heart and loving the neighbor as God requires, and it condemns benumbing sensibility, mingling human wisdom with the divine, confusing minds about right and holy business methods, diverting mission means to ambitious designs, unjustly acquiring means at another's expense, and pleasing the lust for gain and power. Those who do such things prove they have not learned the law and its explanation given on the Mount, and they must repent and be converted to works worthy of the Christian name through a cleansing and purging of the soul temple. It contains lessons not yet learned that call for ordering life by the truth of God found in His word, recognizing every gift as coming from Him, letting gratitude for His goodness fill the heart so that a heavenly atmosphere surrounds the soul, and studying the Scriptures diligently as the truth of the living God, the foundation of faith and the assurance of hope of eternal life in the kingdom of heaven.