Jay Dyer says:
7) "[A consistent Calvinist must be] A Pelagian, in that you have the same view of pre-lapsarian man as Pelagius, and what must be lost is human nature, because nature is grace."
a) The Calvinist Position (whether right doctrine or error let Scripture decide)
Calvinism teaches that Adam was created upright (Genesis 1:31 and Genesis 5:1), although we must be careful not to speculate excessively over Adam's psyche given the limited Scriptural discussion of the subject. However, Adam fell and the race was cursed because of his sin ("Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned:" Romans 5:12). Grace overcomes our fallen nature ("Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved;)" Ephesians 2:5), so that salvation is by grace, not works ("And if by grace, then is it no more of works: otherwise grace is no more grace. But if it be of works, then is it no more grace: otherwise work is no more work." Romans 11:6). Thus, sin reigned to death, but grace reigns to eternal life ("That as sin hath reigned unto death, even so might grace reign through righteousness unto eternal life by Jesus Christ our Lord" Romans 5:21).
Also, see 2(a) previously posted.
A quotation from Charles Hodge's Systematic Theology may be helpful at to explain part of the grace/nature distinction:
Distinction between the Providential Efficiency of God and the Influences of the Holy Spirit
3. The providential agency of God in the government of free agents is not to be confounded with the operations of his grace. These two things are constantly represented in the Bible as distinct. The one is natural, the other supernatural. In the one God acts according to uniform laws, or by his potentia ordinata in the other, according to the good pleasure of his will, or by his potentia absoluta. The control which God exercises over the ordinary acts of men, and especially over the wicked, is analogous to that which He exercises in the guidance of material causes; whereas his agency in the operations of his grace is more analogous to his mode of action in prophecy, inspiration, and miracles. In the former, or in his providential agency over minds, nothing is effected which transcends the efficiency of second causes. In the latter the effects are such as second causes are utterly inadequate to accomplish. The most obvious points of difference between the two cases are,
(1.) In the ordinary operations or acts of free agents, the ability to perform them belongs to the agent and arises out of his nature as a rational creature, and is inseparable from it; whereas the acts of faith, repentance, and other holy affections do not flow from the ability of men in the present condition of their nature, but from a new principle of life supernaturally communicated and maintained.
(2.) The ordinary acts of men, and especially their wicked acts, are determined by their own natural inclinations and feelings. God does not awaken or infuse those feelings or dispositions in order to determine sinners to act wickedly. On the other hand, all gracious or holy affections are thus infused or excited by the Spirit of God.
(3.) The providential government of God over free agents is exercised as much in accordance with the laws of mind, as his providential government over the material world is in accordance with the established laws of matter. Both belong to the potentia ordinata or ordered efficiency of God. This is not the case in the operations of his grace. Holy affections and exercises are not due to the mere moral power of the truth, or its control over our natural affections, but to the indwelling of the Spirit of God. So that it is not we that live but Christ that liveth in us. It is indeed our life, but it is a life divine in its origin, and sustained and guided in all its exercises by a higher influence than the laws of mind, or an influence which operates merely through them, and according to their natural operations. This distinction between nature and grace, between the providential efficiency of God and the workings of his Spirit in the hearts of his people is one of the most important in all theology. It makes all the difference between Augustinianism and Pelagianism between Rationalism and supernatural evangelical religion.
b) The Accusation Disputed
Pelagius was a heretic that opposed Augustine. Pelagius' primary error was denying the necessity of grace - he consequently also denied the sufficiency of grace. Calvinists affirm the necessity of grace, and it is a central aspect of Calvinism to affirm the necessity of grace.
Furthermore, another error of Pelagian was in arguing that people (other than Christ himself) are born without sin. Calvinism, however, affirms the Total Depravity of fallen mankind, making Original Sin a doctrine of central importance in Calvinism. Thus, no consistent Calvinist could be a Pelagian. Any superficial similarity between Calvinism and Pelagius with respect to the state of Adam before the fall would be a trivial matter.
c) The Accusation Redirected
Sadly, rather than being Augustinian, Rome's view of man is semi-Pelagian: affirming the necessity of grace (against Pelagius) but denying its sufficiency. While there are certainly many areas where Calvinists today would find fault with Augustine, on the Pelagian controversy, Calvinists are happy to view Augustine as providing an excellent and Scriptural defense of the truth that God's grace is both necessary for salvation, and sufficient to guarantee salvation for the elect of God. Furthermore, Rome holds to the position (to which we cannot find early documented support than Pelagius) that Jesus was not alone in being immaculately conceived, but that Mary was likewise immaculately conceived.
(Peter Leithart, who I am not endorsing by posting this link, has an interesting related post on Turretin and Pelagius at the link.)
Continue to Part 9