In his day George Peck (1797-1876) was a prominent clergman in the Methodist Episcopal Church in PA and NY. In addition to serving numerous pastorates and appointments as Presiding Elder (now called District Superintendents), he served as the editor of the Methodist Quarterly Review (1848-1851) and was a prolific author and editor of books. His books include The Scripture Doctrine of Christian Perfection Stated and Defended (1848); Sketches and Incidents; or, A Budget from the Saddle-bags of a Superannuated Itinerant (1844-1845); and The Methodist Episcopal Pulpit: A Collection of Original Sermons from Living Ministers of the M. E. Church (1848). A picture of his gravestone can be found here.
Hebrews 6:4-6 has been the source of no small controvery between Arminians and Calvinists. Arminians view the passage as an unequivocal assertion of the possibility and danger of falling from a state of grace. Calvinists, according to Peck, have placed a "variety of constructions" upon it to harmonize it with their doctrine of the perseverance of the saints. Peck notes the principal Calvinistic interpretations (221-222):
1) The "high attainments" mentioned in the passage do not really describe someone in a state of grace.
2) The passage truly describes someone in a state of grace, but the impossibility of renewal to repentance is not an absolute possibility, but only indicates the extreme difficulty of such a renewal.
3) The impossibility only refers to human abilities, but God can and does renew them.
4) The participle παραπεσοντας is given a conditional rendering: "if they shall fall away."
5) The passage talks about a real fall from a state of grace and the impossibility of their being renewed is to be taken literally and absolutely. But this passage does not prove that someone in a state of grace will fall away. God uses such threatenings, in part, to secure their final perseverance.
Peck quotes at length from Moses Stuart's commentary on Hebrews. Stuart was a staunch Calvinist himself, and he effectively refutes the first four interpretations, only to fall back on the fifth interpretation. Peck essentially uses a Calvinist to argue against Calvinists, so all he has to do is dismiss the final interpretation since Stuart has already done the "heavy lifting" for him.
Stuart argues that the adjective αδυνατον cannot have the meaning very difficult, but must be taken in an absolute sense. This is clear by the author's usage of αδυνατον in 6:18; 10:4; and 11:6. (222-223)
In a detailed exegesis of the participial clauses of verses 4 and 5, Stuart notes that there is a progression from one who has been taught the principles and doctrines of Christianity to one who has fully experienced the powers and influences of the world to come. Hence the passage refers to real Christians and not those who merely profess to be so. (223-225)
Peck also quotes from James MacKnight, another Calvinist, who rejects the conditional translation of παραπεσοντας. The participle is in the same tense as all the previous participles, the aorist tense, and so must be translated in the same way--in past time. (225)
Stuart concludes that the language of the passage demonstrates that the writer is "addressing those whom he takes to be real Christians." Moreover, Stuart admits that the penalty is a real threat that Christians could incur (227-228). So, it would seem that Stuart has "abandoned the Calvinistic views of the perserverance of the saints" (228). However, Stuart's interpretation founders on his Calvinistic presuppositions:
Whatever may be true in the Divine purposes, as to the final salvation of all those who are once truly regenerated . . . yet nothing can be plainer, than that sacred writers have every where addressed saints in the same manner as they would address those whom they considered as constantly exposed to fall away and perish for ever. Whatever theory may be adopted in explanation of this subject, as a matter of fact, there can be no doubt that Christians are to be earnestly and solemnly warned against the danger of apostasy, and consequent, final perdition. What else is the object of the whole Epistle to the Hebrews, except a warning against apostasy? In this all agree. But this involves all the difficulties that can be raised by the metaphysical reasonings, in regard to the perseverance of the saints. For why should the apostle warn true Christians . . . against such defection and perdition? My answer would be: Because God treats Christians as free agents, as rational beings; because he guards them against defection, not by physical power, but by moral means, adapted to their natures, as free and rational agents. (228; bold face mine)
Peck has two responses to Stuart's reasoning. First, he turns Stuart's arguments against Universalism (given elsewhere) against him, since a Universalist could use the same reasoning to argue that God treats all people as free agents and rational beings and so he guards them from perdition, not by physical power, but by moral means, adapted to their natures, as free and rational agents--and in fact Universalists do employ such arguments. (228-229) Second, he rejects both the Calvinist and Universalist interpretations since the language employed in Hebrews is so solemn and severe that it would be hard to take it as merely a false alarm. The Calvinist position impugns God's truthfulness to such a degree that it undermines our confidence in God's trustworthiness, for if God can threaten that which He never will execute, what prevents Him from promising that which He will never fulfill? (230)