Because sin is lawlessness (ἀνομία), which God has expressly forbidden, man through sin becomes guilty before God, Rom. 3, 19 (reatus culpae) and subject to His most just punishments, Gal. 3, 10 (reatus poenae). How sin should be punished (the manner and extent of punishment) is not for guilty man to decide, but has been determined and decreed by God Himself, Deut. 9, 5; Rom. 6, 23; Matt. 25, 41.
The transgression of our first parents was immediately followed by death (Gen. 2, 17; Rom. 5, 12) in its threefold aspects as a) spiritual death, inasmuch as they lost the divine image and became alienated from God and entirely corrupt in their whole nature, Gen. 5, 3; John 3, 5. 6; b) temporal death, inasmuch as they were now subject to bodily dissolution with all its incidental diseases and miseries, Gen. 3, 16-19; and c) eternal death, inasmuch as they were now under the curse of eternal damnation, 2 Thess. 1, 9; Matt. 25, 41. However, the sentence of death was stayed by the promise of the divine Redeemer of the sinful human race, Gen. 3, 15. Since all descendants of Adam share in his guilt and corruption, Rom. 5, 12; Ps. 51, 5, all without exception are under the curse and condemnation of the Law, Rom. 3, 19-23. But as they share in Adam's sin, so they share also in the redemption of the Savior who was promised to our first parents, Rom. 5, 15-21.
The guilt and punishment of sin must be constantly emphasized by the Christian theologian, since man in his depravity refuses to believe what the divine Law teaches with regard to sin and its consequences. He denies the temporal punishments of sin (disease, death), explaining them as natural events; and he denies the eternal punishment of sin, Matt. 25, 41; 2 Thess. 1, 9, though his conscience accuses and condemns him, Rom. 1, 32; 2, 15. Even believers, in so far as they are flesh, refuse to believe the severity of God's threats, Ps. 90, 11. 12, and therefore Christ Himself so earnestly proclaimed the truth that the divine punishment of sin is eternal, Mark 9, 43-48.
While the effusions of divine wrath upon the wicked must be regarded as a real punishment for sin (poena vindicativa), the suiferings of believers in this life (1 Cor. 11, 32) are in reality fatherly chastisements (castigationes paternae), which flow not from wrath, but from love (Ps. 94, 12; Reb. 12, 6; Rev. 3, 19), though in form and appearance they do not differ from the punishments of the wicked. Luther rightly calls the chastisement of God's saints a "gracious and joyous punishment."