Since Reformed Protestants (Calvinists) do not believe that Jesus died on the Cross for the sake of all mankind, but rather only a select few (a doctrine called Limited Atonement), one passage often used to refute this error is 1 John 2:1-2,
Jesus is the propitiation for our sins,Taking this plainly, Jesus die for all men, meaning Limited Atonement is refuted and thus so is Calvinism. But since Calvinists can't go down without a fight, they must somehow explain this text. The best they've come up with is saying that the term "world" here does not mean all mankind, but rather "only the select few" or "only the elect Gentiles". But they have no good reason to assume the term "world" here is to be restricted like that. In fact, there's a strong case to be made that John was clearly not speaking of "world" in a restricted sense (hat tip to this Catholic for showing me this), and that can be shown by how Saint John repeatedly uses the Greek word for "world" (Kosmos) in his First Epistle. Consider the 22 other occurrences in the Epistle:
and not for ours only but also for the sins of the whole world.
It's great that John used the term Kosmos so many times since it gives us a better idea of what he possibly could have meant, including a possible meaning of "select few". But using a simple substitution, try inserting "select few" or "select Gentiles" into these texts. The only text that would remain coherent is 1 John 4:14, but that doesn't prove an alternative definition. Thus, the Calvinist attempt to restrict the term "world" fails. While Kosmos is not used the exact same way in each verse, these acceptable definitions completely permit a universal atonement reading of 1 John 2:2.Chapter 2: 15 Do not love the world or the things in the world. If anyone loves the world, the love of the Father is not in him. 16 For all that is in the world—the desires of the flesh and the desires of the eyes and pride of life—is not from the Father but is from the world. 17 And the world is passing away along with its desires, but whoever does the will of God abides forever.Chapter 3: 1 The reason why the world does not know us is that it did not know him. ... 13 Do not be surprised, brothers, that the world hates you. ... 17 But if anyone has the world's goods and sees his brother in need, yet closes his heart against him, how does God's love abide in him?
Chapter 4: 1 Beloved, test the spirits to see whether they are from God, for many false prophets have gone out into the world. ... 3 This is the spirit of the antichrist, which you heard was coming and now is in the world already. 4 Little children, you are from God and have overcome them, for he who is in you is greater than he who is in the world. 5 They are from the world; therefore they speak from the world, and the world listens to them. ... 9 In this the love of God was made manifest among us, that God sent his only Son into the world, so that we might live through him. ... 14 And we have seen and testify that the Father has sent his Son to be the Savior of the world. ... 17 By this is love perfected with us, so that we may have confidence for the day of judgment, because as he is so also are we in this world.
Chapter 5: 4 Everyone who has been born of God overcomes the world. And this is the victory that has overcome the world—our faith. 5 Who is it that overcomes the world except the one who believes that Jesus is the Son of God? ... 19 We know that we are from God, and the whole world lies in the power of the evil one.