1 Corinthians 1:23-24 says, "We preach Christ crucified, a stumbling block to Jews and folly to Gentiles, but to those who are called, both Jew and Greeks, Christ the power of God and the wisdom of God." Notice the two kinds of "calls" implied in this text.
First, the preaching of Paul goes out to all, both Jews and Greeks. This is the general call of the gospel. It offers salvation to all who will believe on the crucified Christ. But by and large it falls on unreceptive ears and is called foolishness.
But then, secondly, Paul refers to another kind of call. He says that among those who hear there are some who are "called" in such a way that they no longer regard the cross as foolishness but as the wisdom and power of God. What else can this call be but the irresistible call of God out of darkness into the light of God? If ALL who are called in this sense regard the cross as the power of God, then something in the call must effect the faith. This is irresistible grace.
It is further explained in 2 Corinthians 4:4-6, "The god of this world has blinded the minds of unbelievers, to keep them from seeing the light of the gospel of the glory of Christ, who is the likeness of God...It is the God who said, 'Let light shine out of darkness,' who has shone in our hearts to give the light of the knowledge of the glory of God in the face of Christ."
Since men are blinded to the worth of Christ, a miracle is needed in order for them to come to see and believe. Paul compares this miracle with the first day of creation when God said, "Let there be light." It is in fact a new creation, or a new birth. This is what is meant by the effectual call in 1 Corinthians 1:24.
Those who are called have their eyes opened by the sovereign creative power of God so that they no longer see the cross as foolishness but as the power and the wisdom of God. The effectual call is the miracle of having our blindness removed. This is irresistible grace.
Another example of it is in Acts 16:14, where Lydia is listening to the preaching of Paul. Luke says, "The Lord opened her heart to give heed to what was said by Paul." Unless God opens our hearts, we will not heed the message of the gospel. This heart-opening is what we mean by irresistible grace.
Another way to describe it is "new birth" or being born again. We believe that new birth is a miraculous creation of God that enables a formerly "dead" person to receive Christ and so be saved. We do not think that faith precedes and causes new birth. Faith is the evidence that God has begotten us anew. "Every one who believes that Jesus is the Christ has been born of God" (1 John 5:1).
When John says that God gives the right to become the children of God to all who receive Christ (John 1:12), he goes on to say that those who do receive Christ "were born, not of blood nor of the will of the flesh nor of the will of man, but of God." In other words, it is necessary to receive Christ in order to become a child of God, but the birth that brings one into the family of God is not possible by the will of man.
Man is dead in trespasses and sins. He cannot make himself new, or create new life in himself. He must be born of God. Then, with the new nature of God, he immediately receives Christ. The two acts (regeneration and faith) are so closely connected that in experience we cannot distinguish them. God begets us anew and the first glimmer of life in the new-born child is faith. Thus new birth is the effect of irresistible grace, because it is an act of sovereign creation—"not of the will of man but of God."
By John Piper. © Desiring God. Website: www.desiringGod.org. Email: mail@desiringGod.org. Toll Free: 1.888.346.4700.