For this reason we must pay much closer attention to what we have heard, so that we do not drift away from it. For if the word spoken through angels proved unalterable, and every transgression and disobedience received a just penalty, how will we escape if we neglect so great a salvation? After it was at the first spoken through the Lord, it was confirmed to us by those who heard, God also testifying with them, both by signs and wonders and by various miracles and by gifts of the Holy Spirit according to His own will.
John Calvin comments: “It is not only the rejecting of the Gospel, but even the neglecting of it that deserves the severest penalty in view of the greatness of the grace which is offered in it. Therefore he says--so great salvation. God wishes His gifts to be valued by us at their proper worth. The more precious they are, the baser is out ingratitude if they do not have their proper value for us. In accordance with the greatness of Christ, so will be the severity of God’s vengeance on all despisers of the Gospel.” (Calvin’s New Testament Commentaries: Hebrews and I and II Peter, p.19, emphasis mine)
Calvin adds: “Notice that the word ‘salvation’ is applied here by metonymy to the doctrine, because, just as God wills that men should be saved in no other way than through the Gospel, so when it is neglected the whole salvation of God is rejected.” (Calvin’s New Testament Commentaries: Hebrews and I and II Peter, p.19, emphasis mine)
Calvin writes: “But here he runs full sail against God for determining some from their very creation to destruction.” (Concerning the Eternal Predestination of God, p.78, emphasis mine)
Calvin writes: “At this point in particular the flesh rages when it hears that the predestination to death of those who perish is referred to the will of God.” (Calvin’s New Testament Commentaries: Romans and Thessalonians, p.208, emphasis mine)
Calvin states: “If we are not ashamed of the gospel, we must confess what is there plainly declared. God, by His eternal goodwill, which has no cause outside itself, destined those whom He pleased to salvation, rejecting the rest; those whom He dignified by gratuitous adoption He illumined by His Spirit, so that they receive the life offered in Christ, while others voluntarily disbelieve, so that they remain in darkness destitute of the light of faith.” (Concerning the Eternal Predestination of God, p.58, emphasis mine)
Calvin addresses the contradiction:
John Calvin writes: “That Christ, the redeemer of the whole world, commands the Gospel to be preached promiscuously to all does not seem congruent with special Election. ... But the solution of the difficulty lies in seeing how the doctrine of the Gospel offers salvation to all. That it is salvific for all I do not deny. But the question is whether the Lord in His counsel here destines salvation equally for all.” (Concerning the Eternal Predestination of God, pp.102, 103, emphasis mine)
Often times, in what are called “warning passages,” if the Calvinist infers that it is speaking exclusively of the Calvinistically elect, then the Calvinist will merely infer that they are hypothetical warnings, which never actually come to fruition, and merely serves to keep the Calvinistically elect in line.