1 John 2:2
My little children, I am writing these things to you so that you may not sin. But if anyone does sin, we have an advocate with the Father, Jesus Christ the righteous. 2 He is the propitiation for our sins, and not for ours only but also for the sins of the whole world. 1 John 2:1-2 (ESV)
(For a better and more recent defense see here.)
The first word to examine is propitiation. Propitiation (ἱλασμός, G2434) means the appeasement of (divine wrath of) God. Thus it means the forgiveness of sins as seen for example in Rom 3:25, 1 Jn 4:10. If we take the “sins of the world world” to mean the sins of every single individual who has ever lived, then we have Universalism on our hands, which is not consistent with the whole testimony of the Bible. Second, we know from the Bible that we have to believe to be saved, we need to have faith to be redeemed (Rom 10:9-10; c.f. “Repentance and faith are necessary for salvation”).
There is a passage in the Gospel according to John that is very similar to 1 Jn 2:2 and I believe it will help us understand what 1 Jn 2:2 is talking about. The passage is Jn 11:51-52.
|1 John 2:2||John 11:51-52|
|He is the propitiation for our sins,||…he prophesied that Jesus would die for the nation,|
|and not for ours only||and not for the nation only,|
|but also for the sins of the whole world.||but also to gather into one the children of God who are scattered abroad.|