The mortality of man is the doctrine that man, as he now is, is subject to death—and that this mortality is not original to his creation but entered as the penal consequence of sin. God did not create man to die; He created him upright and placed him under a covenant in which life was promised for obedience and death threatened for transgression. Death entered the world by sin: “by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned.” The wages of sin is death, and this death is the appointed lot of all Adam’s race: it is appointed unto men once to die, and after this the judgment. Mortality is therefore penal—a curse, an enemy, the rending of body and soul that God pronounced upon the breaking of His covenant: “dust thou art, and unto dust shalt thou return.” This must be carefully distinguished from the immortality of the soul: it is the body that returns to dust, and the person that suffers the unnatural separation of soul from body; the soul itself does not perish but continues consciously. Death is thus no natural friend nor mere transition, as the world would soothe itself to believe, but the last enemy, an intrusion into God’s good creation, the sign and seal of sin’s reign. Yet the gospel transforms its meaning for the believer. Christ, the second Adam, bore the penalty of death in His people’s place, conquered it in His resurrection, and abolished death, bringing life and immortality to light. For those in Christ, death’s sting—which is sin—is removed; it remains an enemy, but a defeated one, the doorway by which the soul passes to be with Christ, awaiting the resurrection when this mortal shall put on immortality and death shall be swallowed up in victory. The doctrine of man’s mortality thus teaches the gravity of sin (whose wage is death), the comfort of the gospel (which conquers death), and the wisdom of numbering our days, that we may apply our hearts unto wisdom and be ready to meet our God.