1 John 2:2 Destroys Limited Atonement
Source: vaticancatholic.com

Calvinists believe in Limited Atonement. That’s the idea that Christ did not shed His blood for all men but only for the elect. A number of verses contradict this heresy. 1 John 2:2 is a good example.
1 John 2:2: “He is the propitiation for our sins, and not for ours only but also for the sins of the whole world (ὅ__λου το__ῦ κόσμου).”
St. John teaches that Christ died not just for “our sins” (meaning the sins of the faithful), but also for the sins of the whole world. This is clear enough. However, this passage becomes even more potent in refuting Calvinism when you consider how St. John consistently uses the word κόσμος (meaning “world”) in his epistle. St. John repeatedly uses the word κόσμος (“world”) to describe unbelievers and the world that is outside of God or hostile to Him. Here are four examples to demonstrate the point.
1 John 3:1: “See what kind of love the Father has given to us, that we should be called children of God; and so we are. The reason why the world does not know us (ὁ κόσμος οὐ γινώσκει ἡμᾶς) is that it did not know him.”
In 1 John 3:1 “the world” refers to those who do not believe or know God.
1 John 3:13: “Do not be surprised, brothers, that the world (ὁ κόσμος) hates you.”
In 1 John 3:13 “the world” refers to those who are anti-Christian.
1 John 4:4: “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 (μείζων ἐστὶν ὁ ἐν ὑμῖν ἢ ὁ ἐν τῷ κόσμῳ).”
In 1 John 4:4 “the world” refers to people who are not “from God”, which means that they have not been born again and entered the Church.
1 John 5:19: “We know that we are from God, and the whole world lies in the power of the evil one (ὁ κόσμος ὅλος ἐν τῷ πονηρῷ κεῖται).”
In 1 John 5:19 “the world” refers to those who are under the power of the Devil and not in the Kingdom of God on earth.
Hence, when St. John says in 1 John 2:2 that Christ is the propitiation not only for our sins, but for the sins of “the whole world”, that obviously includes people who will never believe and are not among the elect. To claim otherwise is absurd. Calvinism is clearly contrary to the teaching of the Bible. However, the Catholic position is true and biblical.
Pope Paul III, Council of Trent, Decree on Justification, Sess. 6, Chap. 3: “But although Christ died for all, yet not all receive the benefit of His death, but those only to whom the merit of His Passion is communicated.”
