"The sin of Adam," says Charles Hodge, "did not make the condemnation of all men merely possible; it was the ground of their actual condemnation. So the righteousness of Christ did not make the salvation of men merely possible, it secured the actual salvation of those for whom He wrought."While God's love is unconditional, salvation is not. Therefore, it says, "God so loved the world that He gave His only begotten Son, that whosoever believes in Him shall not perish but have eternal life." (Jn.3:16). The Atonement of Christ is God's provision for the salvation of the world. However, only those who make an independent choice to believe are saved.
The great Baptist preacher Charles H. Spurgeon said: "If Christ has died for you, you can never be lost. God will not punish twice for one thing. If God punished Christ for your sins He will not punish you. 'Payment God's justice cannot twice demand; first, at the bleeding Saviour's hand, and then again at mine.' How can God be just if he punished Christ, the substitute, and then man himself afterwards?", Loraine Boettner, The Reformed Doctrine of Predestination.
While all men inherit death because of Adam’s sin, all men will not unconditionally inherit life because of the righteousness of Christ (Romans 5). Faith is the condition for justification. While in Adam, death “spread to all men” (Rom.5:12), in Christ righteousness is “imputed” to those who believe (Rom.4:24). In Adam, one talks of generations to whom death is passed by one man. In Christ, every person is given the opportunity to make his/her personal, independent, choice and be justified. Those who make this second, independent, Adamic choice to persist in the autonomy of Adam will inherit Second Death. Those who accept the Death of Christ (the Last Adam) will inherit the newness of eternal life of the Resurrected Second Man (1Cor.15:47).
Humanity fell by one man’s choice; but, each human is saved by his own single choice. Therefore, in the resurrection, the saints are a multitude of sons (not sons, grandsons, and great grandsons). [See Full Article]