“Rejoice in the Lord always; again I will say, rejoice.” (Philippians 4:4)
Since there exist in the heart these two things- a consciousness of sin and a perception of God's chastisement, the heart must ever be depressed, faint, even terrified. It must be the just and the righteous who are to rejoice in the Lord. First we must be liberated from our sins and perceive a merciful God. When we have been released from the power of an evil conscience, joy will result naturally.
But how shall we be liberated from an accusing conscience and receive the assurance of God's mercy? He who would have a quiet conscience, and would be sensitive to God's mercy, must not depend on works, still further doing violence to the heart and increasing its hatred of God. He must place no hope whatever in works; but must apprehend God in Christ, comprehend the Gospel and believe its promises.
What does the Gospel promise other than that Christ is given for us; that he bears our sins; that he is our Bishop, Mediator, and Advocate before God, and that only through him and his work is God reconciled, are our sins forgiven and our consciences set free and made glad? When this sort of faith in the Gospel really exists in the heart, God is recognized as favorable and pleasing. The heart confidently feels his favor and grace, and only these. It fears not God's chastisement. It is secure and in good spirit because God has conferred upon it, through Christ, superabundant goodness and grace. The fruit of such a faith is love, peace, joy, and songs of thanksgiving and praise. It will enjoy unalloyed and sincere pleasure in God as its supremely beloved and gracious Father, a Father whose attitude toward itself has been wholly paternal, and who, without any merit on its part, has richly poured out upon that heart his goodness.
Such is the rejoicing of which Paul speaks--a rejoicing where there is no fear of death or hell, but rather a glad and all-powerful confidence in God and his kindness. Hence the expression, "Rejoice in the Lord"; not rejoice in silver or gold, not in eating or drinking, not in mechanical chanting, not in strength or health, not in skill or wisdom, not in power or honor, not in good works or holiness even. For these are deceptive joys, false joys, which never stir the depths of the heart. They are never even felt. When they are present we may well say the individual rejoices superficially. To rejoice in the Lord--to trust, confide, glory and have pride in the Lord as in a gracious Father--this is a joy which rejects all else but the Lord, including all self-righteousness.