According to this definition of Monergism:
Monergism (monergistic regeneration) is a redemptive blessing purchased by Christ for those the Father has given Him (1 Pet 1:3, John 6:37, 39). This grace works independently of any human cooperation and conveys that power into the fallen soul whereby the person who is to be saved is effectually enabled to respond to the gospel call (Acts 2:39, 1 Cor 1:2, 9, 24, Rom 8:30 John 1:13, Acts 13:48). It is that supernatural power of God alone whereby we are granted the spiritual ability and desire to comply with the conditions of the covenant of grace; that is, to apprehend the Redeemer by a living faith, to come up to the terms of salvation, to repent of idols and to love God and the Mediator supremely. The Holy Spirit, in quickening the soul, mercifully capacitates and inclines God’s elect to the spiritual exercise of faith in Jesus Christ (John 6:44, 1 John 5:1). This instantaneous and intensely personal work of God is the means by which the Spirit brings us into living union with Him. . . .
To summarize, those dead in sin (Eph 2:1,5,8), play no part in their own new birth (Rom 3:11, 12; 8:7) and are just as passive as a new born physical baby in the regenerative act. However, once restored with a new sense and given spiritual understanding through Word and Spirit, the soul’s new disposition immediately plays an active roll in conversion (repentance and faith). Thus, man does not cooperate in his regeneration but rather, infallibly responds in faith to the gospel as the Holy Spirit changes our hearts’ disposition (John 3:6-8; 19-21). Faith is, therefore, not something produced by our unregenerated human nature. The fallen sinner has no moral ability or inclination to believe prior to the new birth. Instead, the Holy Spirit must open one’s ears to the preaching of the gospel if one would desire to hear and believe.
Jonathan Edwards, Charles Spurgeon, Martin Luther (who considered this doctrine the heart of the Reformation), John Calvin, John Owen, the Puritans of the 17th century, Augustine, George Whitefield, and some contemporary pastors and theologians such as Martyn Lloyd-Jones, John Piper, Wayne Grudem, R.C. Sproul, D.A. Carson, Michael Horton, J.I. Packer, James Montgomery Boice, and signatories to the Alliance of Confessing Evangelicals.
In other words, by “historic church” he means only the church of the last five hundred years. (He also mischaracterizes St. John Cassian as a semi-Pelagian, which is just false.)
But in fact, the historic, biblical and orthodox belief of the Church about soteriology is one of synergism, which is exemplified in the following passages (though others could be mentioned), which the author himself avoids:
For by grace you are saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast. For we are His handiwork, created in Christ Jesus for good works, which God prepared beforehand that we should walk in them. (Ephesians 2:8-10)
So then, my beloved, just as you have always obeyed, not as in my presence only, but now much more in my absence, work out your own salvation with fear and trembling; for it is God who is working in you, both to will and to do for His good pleasure. (Philippians 2:12-13)
What does it profit, my brothers, if someone says he has faith but does not have works? Is that kind of faith able to save him? if a brother or sister is naked and destitute of daily food, and one of you says to them, “Go in peace, be warmed and filled,” but you do not give them the necessary things of the body, what is the benefit? Thus also that faith, if it does not have works, is dead, being by itself. But someone will say, “You have faith, and I have works.” Show me your faith apart from your works, and I will show you my faith by means of my works. You believe God is one. You do well. Even the demons believe–and they shudder! But do you want to know, O foolish man, that faith without works is dead? Was not Abraham our father justified by works when he offered Isaac his son on the altar? Do you see that faith was working together with his works, and by means of his works faith was made perfect? And the Scripture was fulfilled which says, “Abraham believed God, and it was accounted to him for righteousness.” And he was called a friend of God. You see then that a man is justified by works, and not by faith only. Likewise, was not Rahab the harlot also justified by means of works, when she received the messengers and sent them out another way? For as the body without the spirit is dead, so faith without works is dead also. (James 2:14-26)
For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and became partakers of the Holy Spirit, and have tasted the good word of God and the powerful deeds of the age to come, and having fallen away, to renew them again to repentance, since they crucify again for themselves the Son of God, and hold Him up to contempt. For the earth which drinks the rain often coming upon it, and bears suitable vegetation for those on account of whom it is cultivated, receives a blessing from God; but if it bears thorns and thistles, it is worthless and near to being cursed, of which the end is for burning. But we are persuaded concerning you, beloved, of better things and those pertaining to salvation, even though we speak in this manner. For God is not unjust to forget your work and labor of love which you have shown toward His name, in that you have ministered to the saints, and do minister. But we desire that each one of you show the same diligence to the full assurance of hope until the end, lest you become dull, but become imitators of those who through faith and patience inherit the promises. (Hebrews 6:4-12)
Let us hold fast the confession of our hope without wavering, for He who promised is faithful. And let us consider one another for the stirring up of love and of good works, not forsaking the assembling of ourselves, just as is the custom for some, but exhorting one another, and all the more as you see the Day drawing near. For if we sin willfully after receiving the knowledge of the truth, there no longer remains a sacrifice for sins, but a certain fearful expectation of judgment, and fiery zeal being about to devour the adversaries. Anyone disregarding the law of Moses dies without compassions on the testimony of two or three witnesses. By how much worse punishment, do you think, will he be deemed worthy who has trampled the Son of God underfoot, and has regarded as common the blood of the covenant, by which he was sanctified, and has insulted the Spirit of grace? For we know Him who said, “Vengeance is Mine; I will repay,” says the Lord. And again, “The LORD will judge His people.” It is a fearful thing to fall into the hands of the living God! But remember the former days, in which after you were enlightened, you endured a great struggle of sufferings, in part being exposed publicly, both to reproaches and to afflictions, and in part having become partners of those treated in this way. For you sympathized with me in my chains, and you received the plunder of your possessions with joy, knowing that you have for yourselves a better and enduring possession in heaven. Therefore do not cast away your confidence, which has a great recompense. For you have need of endurance, so that having done the will of God, you may receive the promise: “For yet a little while, and He who is coming will come and will not delay. But the just shall live by faith, and if he withdraws, My soul has no pleasure in him.” But we are not of those shrinking back to destruction, but of faith, to the saving of the soul. (Hebrews 10:23-39)
Unfortunately, the afore-cited monergist defines synergism as a strawman which he then knocks down:
Before defining monergism, we should start on more familiar ground to 21st century man by explaining the more familiar “synergism”, which the majority of our churches teach today. Synergism is the doctrine that the act of being born again is achieved through a combination of human will and divine grace. (From Greek sunergos, working together : sun-, syn- + ergon, work). The Century Dictionary defines synergism as
“…the doctrine that there are two efficient agents in regeneration, namely the human will and the divine Spirit, which, in the strict sense of the term, cooperate. This theory accordingly holds that the soul has not lost in the fall all inclination toward holiness, nor all power to seek for it under the influence of ordinary motives.”
In other words, synergists believe that faith itself, a principle standing independent and autonomous of God’s action of grace, is something the natural man must add or contribute toward the price of his salvation. Unregenerate man, in this scheme, is left to his freewill and natural ability to believe or reject God. Synergists teach that God’s grace takes us part of the way to salvation but that the [fallen, rebellious] human will must determine the final outcome. It does this by reaching down into an autonomous principle within in its fallen unrenewed nature in order to either produce a right thought or create a right volition toward God.
He then goes on to create this chart which similarly mischaracterizes synergism.
In point of fact, as the above Scriptural texts show, it is not a 50-50 proposition, that “God takes us halfway” but then we “add” the rest. In point of fact it is a 100-100 proposition, in which the human agent and God are united in total to one another. Monergism posits an either/or: either man is not fallen and can act to receive grace, or man is fallen and cannot act to receive grace. But according to the teaching of the historic Church, man is fallen and can act to receive grace. In other words, orthodoxy rejects the necessary presupposition of monergism that man is totally depraved not merely forensically but volitionally, and that such depravity excludes free will. But if one takes away that presupposition, monergism cannot go forward in its argument.
Furthermore, the principle of orthodox soteriology is based on the doctrine of the Incarnation and the condemnation of the belief of only one will (the divine will) in Christ at the Sixth Ecumenical Council, a heresy known as monothelitism.
As the Councils taught, Christ has two natures and two wills in one Person. For if Christ did not have both a human will and nature and a divine will and nature, the human will and nature could not be saved. But if Christ has assumed human nature and will, then the teaching that human will is not free is to assume that Christ’s human will was not free, and that Christ, himself, in his human will could not act in concert with the will of God, except that only the divine will in himself is operative. But this is to teach heresy. For as Scripture clearly indicates, Jesus’ two wills cooperated in the work of our redemption:
Therefore He was obligated to become like His brothers in all respects, in order that He might become a merciful and faithful High Priest in things pertaining to God, in order that He might make propitiation for the sins of the people. (Hebrews 2:17)
For we do not have a High Priest who cannot sympathize with our weaknesses, but having been tempted in all respects in quite the same way as we are, yet without sin. (Hebrews 4:15)
Just as He also says in another place: “You are a priest forever according to the order of Melchizedek”; who [Jesus], in the days of His flesh, when He had offered up both prayers and supplications, with strong crying and tears to the One who was able to save Him from death, and was heard because of His fear of God, though He was a Son, He learned obedience by the things which He suffered. And having been perfected, He became the author of eternal salvation to all who obey Him . . . (Hebrews 5:6-9)
Then Jesus said to them, “My soul is deeply grieved, to the point of death. Stay here and watch with Me.” He went a little farther and fell on His face, and prayed, saying, “O My Father, if it is possible, let this cup pass from Me; nevertheless, not as I will, but as You will.” Then He came to the disciples and found them sleeping, and said to Peter, “What? Were you not strong enough to watch with Me one hour? Watch and pray, lest you enter into temptation. Indeed the spirit is willing, but the flesh is weak.” Again, a second time, He went away and prayed, saying, “O My Father, if this cup cannot pass away from Me unless I drink it, let Your will be done.” (Matthew 26:38-42)
In other words, Jesus’ human will was brought into conformity with the divine will, meaning human will was and is free to respond to God. Otherwise, any discussion of human volition, pre- or post-regeneration, is moot. Even if we posit that human will was in bondage up until the ministry of Christ (which creates all kinds of problems with regard to Old Testament saints), post-Resurrection the human will is free in the hypostasis of the Son (Cf. Romans 5:12-19)
(For an important theologian and his teaching on free will, divine Providence and salvation, cf. St. John of Damascus, An Exact Exposition of the Orthodox Faith, Books II.24-III.1 [link starts at Bk II.24].)
In other words, monergists do two things: they separate out soteriology from Christology and effectively deny human free will of Christ, which is no different than teaching monothelitism, and thus espousing a heresy.