The question in dispute when it comes to the fourth letter in TULIP is the kind of grace God acts out of towards His creation. Is it what the Roman Catholics believe grace to be; a thing which can be gained or lost, and something to be worked for? Is it grace in the general sense where God makes it to rain on the just and on the unjust (Matt. 5:45)? Or is it saving grace?
Of course, the very definition of grace (unmerited favor) does away with the Roman Catholic view of grace. Grace is not a 'thing' as they believe it to be. If it were, then it would inevitably be something that could be gained or lost; something tangible that could be distributed by sacraments and rituals. Grace, or unmerited favor, is a disposition or bent of God towards whom He chooses. Unmerited means that no one can earn it by any good act or fail to obtain it because of many bad acts. Favor means that grace is a feeling or disposition which produces an act, not anything tangible to be distributed. Grace is the disposition out of which God acts. If God is bent towards being gracious, He will inevitably act on it. Therefore, grace cannot be a thing to be earned, gained, or lost as the Roman Catholics believe.
There are two biblical aspects to the grace of God: a general, universal grace given to all, and saving grace. The first is a grace which we all experience with each breath we take. Because of our fallen nature, God would be perfectly just to snuff out our lives at any instant and send us to hell for eternity, for such is sin's wage. To say we deserve this general grace is to misunderstand grace completely. Every breath, every look, every movement of our joints and muscles is possible only because God is gracious to us in each moment. This grace is given to all who are living. Further still, our daily stations we find ourselves working in are due to the grace of God. If it is true that God makes it to rain on the righteous and unrighteous alike, both the righteous and unrighteous farmers who plant crops are fully dependent on God to act out of grace towards them for there to be a harvest. And if such is the case, the rule can be applied to every other work; if God is not gracious, we will not have work.
The second aspect of grace is the saving grace of God. Without this grace, we have nothing. God would not only keep His benevolent hand from us, but we would never escape our state of sin. Indeed, if God were not gracious, Adam and Eve would have expired as soon as they ate the forbidden fruit. So we must have grace; grace is the reason we exist.
If unconditional election was not enough to convince you of the vastness of God's grace, irresistible grace comes along to, once more, exalt the grace of God. Because this doctrine is most concerned with saving grace, many have renamed it irresistible call. This doctrine deals with the application of the atoning work of Christ to the heart of the sinner, transforming their life forever. It was the response to the Arminian idea which claimed that saving grace is something that is able to be resisted. What this argument boils down to is whether God is sovereign in applying salvation to the sinner, or whether man has the complete freedom from God's influence to choose to be saved or not. In essence, the argument is about sovereignty.
The Arminians never admit outright to placing man as complete sovereign over himself, but their outworking of saving grace always drifts towards the idea that man is the captain of his soul. In the Articles of Remonstrance, saving grace is given to those who, on the basis of prevenient grace, choose to be saved. The Canons of Dort reject this notion by pointing out that the Arminian doctrine of a grace, which makes the will able to freely choose, is a foundation of pride. According to the Arminian, if you are to be saved, you must distinguish yourself above others. If you make the choice, the glory goes to you. Clearly, you must be superior because of your choice; everyone had equal opportunity, but you were the one who was saved. Such is nonsense in itself, for we know that pride is sin, and we must reject all doctrine which causes pride.
Instead, the Calvinists seek to place all glory onto God. "[Conversion] must be wholly of God," the Synod of Dort concluded, "who has chosen His own from eternity in Christ, so He confers upon them faith and repentance, rescues them from the power of darkness, and translates them into the kingdom of His own Son" (Third and Fourth Head of Doctrine, Article 10). It is God who gives faith (Rom. 10:17), and it is God who gives true repentance (2 Cor. 7:10). God not only chooses whom He wills from eternity past, He effectually works in their hearts to apply the atonement of Christ and effectually regenerate them. The Canons of Dort go on to say that God's work is not lacking in any measure to deal with the sin of the sinner.
"He not only causes the gospel to be externally preached to them and powerfully illuminate their minds by His Holy Spirit, that they may rightly understand and discern the things of the Spirit of God; but by the efficacy of the same regenerating Spirit, pervades the inmost recesses of the man; He opens the closed, and softens the hardened heart, and circumcises that which is uncircumcised, infuses new qualities into the will, which though heretofore dead, He quickens; from being evil, disobedient, and refractory, He renders it good, obedient, and pliable; actuates and strengthens it, that like a good tree, it may bring forth the fruits of good actions" (Article 11).
Irresistible grace is not some fabrication of man. Throughout the Bible, it is clearly displayed that God's gracious work in the lives of sinners is never resisted. “But God, being rich in mercy, because of the great love with which he loved us, even when we were dead in our trespasses, made us alive together with Christ—by grace you have been saved" (Eph 2:4-5 ESV). There is a contrast between dead sinners and a God who acts. No dead person has ever resisted any action done toward them. This is not just Paul's idea, Jesus also teaches this.
All that the Father gives me will come to me, and whoever comes to me I will never cast out. (John 6:37)
Again, the link between those whom the Father gives and those who come clearly is not our works. Look at the language used. All whom the Father gives to Christ will come to Christ. There is certainty that those whom God gives to Christ will not resist.
The opposition to this teaching is mostly centered on the idea of free will. If we have a free will, God's grace will always be resistible. There is a sense in which we resist the grace of God; our sin causes us to despise God and His work. However, such is not enough to stall or hinder God from working in our lives. If we have such a tight grip on our free will, we will be led to believe that God only helps those who help themselves – even when the biblical account clearly displays God only helping those who cannot help themselves.
Instead, this doctrine of irresistible grace does not do away with our wills but gives us hope. If we hold to the doctrine of radical depravity, only irresistible grace can save us. Indeed, our view of sin will always dictate our view of grace. Irresistible grace does not deny that we have a will but claims that sin binds our wills so that we cannot choose what is truly good until we are regenerated (a demonstrably biblical teaching).
So it is at this doctrine that the Arminian notion of sin comes to light, and the reality that the Articles of Remonstrance break the law of non-contradiction at worst, and maintain unbiblical doctrine at best, is observed. It is both contradictory and unbiblical to say that man is sinful by nature and a free moral agent at the same time. It seems that any attempt the Arminians make to be biblical in the framework of their five doctrines renders them inconsistent, and any attempt to reconcile their doctrines makes them unbiblical.
There are many people throughout the Bible who would not be surprised at the response of the Calvinists to the idea of resistible grace. Without a doubt, King Nebuchadnezzar would be among that number. If you remember, King Nebuchadnezzar, in a moment of pride as he ascribed glory for himself because of his kingdom, was humiliated by God to walk on all fours and graze grass like the beasts of the field. When his sanity returned, his outlook on life was different – he now ascribed glory to God: "All the inhabitants of the earth are accounted as nothing, and he does according to his will among the host of heaven and among the inhabitants of the earth; and none can stay his hand or say to him, "What have you done?"" (Daniel 4:35 ESV). No one can resist the work of God, and King Nebuchadnezzar found that out in short order. This is the reason saving grace is irresistible. If God decides to act out of grace toward sinners, who is going to stop Him?
It is the Christians joy to know that God acts out of grace towards them. What hope is there, in our sinful state, to hear that God is unable to save us fully? If we are honest with ourselves, we are not steadfast enough, nor strong enough to be relied upon for something as grand as salvation. O how fickle we often are in this life, unsure of what we ought to do! Take heart; we too are able to say with Paul, "His grace towards me was not in vain." Indeed, it never will be because it is God who is at work in us to do what pleases Him best.