Irresistable grace is the I in TULIP. When the gospel had been preached to Gentiles, according to Acts 13:48, "As many as had been appointed to eternal life believed".
We might understand this statement to mean that the gospel answered the needs and desires of every good person whose heart was inclined or disposed toward God, and who sought repentance and forgiveness of sin. That's not how the “irresistable grace” doctrine understands it.
The Calvinistic interpretation of that verse is this: Those who believed did so because they could not possibly resist, and those who disbelieved did so because they could not possibly accept. One could believe only if foreordained to do so, and if foreordained to do so, one could not resist or reject. This idea is known as "irresistable grace".
To understand this doctrine properly, we need to think about God's will and human nature.
In the passage quoted above (Acts 13:48), we see two elements at work:
By designating beforehand the conditions of salvation, God has not only denied eternal life to all those who resist and refuse to meet those conditions, but God has at the same time appointed for eternal life all who are disposed to receive, believe, and obey those conditions (see note). That is the idea behind Acts 13:48.
Of course, this assumes that...
These seem to be strongly implied in the invitation of the Bible, "Whosoever will, let him take of the water of life freely" (Revelation 22:17 cf Matthew 11:28)
But Calvinists could not accept this, because it would be inconsistent with other parts of the TULIP —in particular, their view of human nature.
Human Depravity Calvinists do not consider that there are any good folk whose hearts are disposed toward God and who seek him of their own accord. We studied the Calvinistic view of human nature in the entitled "Total Depravity".
That concept of human depravity leads Calvinists to believe that no human being has any natural disposition toward the word of God. Human beings, by their very "fallen nature" must resist the word of God, and have no choice or ability whatever to desire it or accept it..
This view is inconsistent with the fact that Christ himself had human nature, yet he was a good man disposed toward God and undefiled (Hebrews 2:17).
Unconditional Grace Calvinists do not believe in conditions of salvation. We have already studied the Calvinistic view of salvation in the lesson entitled "Unconditional Election".
That concept of saving grace leads Calvinists to believe that no attitude or action on the part of a person contributes in any way to that person's salvation.
The Calvinist’s view of "free grace" leaves no room for people to make a choice to believe and do certain things as conditions of their salvation. Calvinists think that God would obligate himself if he placed conditions upon his grace, because anyone who fulfilled those conditions would then have a claim upon God. Thus his grace would not be "free".
This view overlooks a salient fact, namely that the most important condition (that an acceptable sacrifice be offered for sin) is beyond anyone's ability to fulfill, and it was grace that provided the needed sacrifice, leaving us always obligated to God, rather than he to us, no matter how many other conditions we can and do fulfill (Hebrews 10:10).
Sovereignty of God Calvinists have a peculiar (in the sense of their own special) view of the sovereignty of God's will. They believe that everything happens according to the predetermined purpose and counsel of God. They hold the philosophy that God must foreordain "whatsoever comes to pass", otherwise his will is not sovereign and he is not omnipotent.
To state that in simple language, if somebody can reject or resist God's will, then that person has a stronger will than God’s.
The Calvinist cannot conceive of God laying down two alternatives, pointing out the eternal and unchangeable consequences of each, and giving a person the choice, especially when God's will favours one alternative and abhors the other.
Calvinists argue that if a person can possibly choose the alternative that God does not wish, then that person's will can prevail over God's will, so the will of that person is the sovereign will, and God's will is subject to that person's own will.
This view overlooks the fact that our Lord himself was tempted and could have disobeyed his Father's will. He said that he would yield to his Father's will; but he also said that he could call upon his Father for twelve legions of angels to escape the cross —even though the Father’s will, written in prophecy, would then fail to be fulfilled (Matthew 26:39,53).
Special attention needs to be given to the use of τασσω (tasso) in Acts 13:48 by comparison with 1Corinthians 16:15. In the latter passage, the household of Stephanas devoted themselves for ministry.
In Acts 13:48 certain Gentiles at Antioch in Pisidia believed Paul’s preaching because they had been devoted to eternal life. God fearing people, they sought light and salvation. Thus disposed, they were designated for eternal life —something which, unfortunately, is unthinkable to a Calvinist.