John MacArthur and many other people who call themselves Calvinists don't actually believe that Jesus died for the sins of the whole world. This is not the historical view of the church and even the reformers believed that Christ died for the sins of the whole world.
John 1:29 The next day John saw Jesus coming toward him, and said, "Behold! The Lamb of God who takes away the sin of the world!
And when he says, the sin Of The World, he extends this favor indiscriminately to the whole human race; - John Calvin
John 3:16-17 For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life. For God did not send His Son into the world to condemn the world, but that the world through Him might be saved.
And he has employed the universal term whosoever, both to invite all indiscriminately to partake of life, and to cut off every excuse from unbelievers. Such is also the import of the term World, which he formerly used; for though nothing will be found inthe world that is worthy of the favor of God, yet he shows himself to be reconciled to the whole world, when he invites all men without exception to the faith of Christ, which is nothing else than an entrance into life. - John Calvin
John 4:42 Then they said to the woman, "Now we believe, not because of what you said, for we ourselves have heard Him and we know that this is indeed the Christ, the Savior of the world."
John 6:51 I am the living bread which came down from heaven. If anyone eats of this bread, he will live forever; and the bread that I shall give is My flesh, which I shall give for the life of the world."
John 12:47 And if anyone hears My words and does not believe, I do not judge him; for I did not come to judge the world but to save the world.
Why then does Christ not choose to condemn them? It is because he lays aside for a time the office of a judge, and offers salvation to all without reserve, and stretches out his arms to embrace all, that all may be the more encouraged to repent. - John Calvin
1 John 2:2 And He Himself is the propitiation for our sins, and not for ours only but also for the whole world.
1 John 4:14 And we have seen and testify that the Father has sent the Son as Savior of the world.
2 Peter 2:1 But there were also false prophets among the people, even as there will be false teachers among you, who will secretly bring in destructive heresies, even denying the Lord who bought them, and bring on themselves swift destruction.
Hebrews 2:9 But we see Jesus, who was made a little lower than the angels, for the suffering of death crowned with glory and honor, that He, by the grace of God, might taste death for everyone.
1 Timothy 4:10-11 For to this end we both labor and suffer reproach, because we trust in the living God, who is the Savior of all men, especially of those who believe. These things command and teach.
Paul makes grace common to all men, not because it in fact extends to all, but because it is offered to all. Although Christ suffered for the sins of the world, and is offered by the goodness of God without distinction to all men, yet not all receive Him. - John Calvin (Romans 5:18)
It is also a fact, without controversy, that Christ came to atone for the sins “of the whole world.” But the solution of all difficulty is immediately at hand, in the truth and fact, that it is “whosoever believeth in Him” that “shall not perish, but shall have eternal life.” John Calvin (Treatise on Eternal Predestination)
For it is the will of God that we should seek the salvation of all men without exception, as Christ suffered for the sins of the whole world. - John Calvin Commentary (Galatians 5:12)
Martin Luther
You may say: “Who knows whether Christ also bore my sin? I have no doubt that He bore the sin of St. Peter, St. Paul, and other saints; these were pious people. Oh, that I were like St. Peter or St. Paul!” Don’t you hear what St. John says in our text: “This is the Lamb of God, who takes away the sin of the world”? And you cannot deny that you are also part of this world, for you were born of man and woman. You are not a cow or a pig. It follows that your sins must be included, as well as the sins of St. Peter or St. Paul. And just as you are unable to expiate your sins, so they have been unable to expiate theirs. There are no exceptions here. Therefore do not yield to your own thoughts, but cling to the words which guarantee you and all believers forgiveness of sin through the Lamb. Don’t you hear? There is nothing missing from the Lamb. He bears all the sins of the world from its inception; this implies that He also bears yours, and offers you grace. - Martin Luther (John 1:29)