The text says that Christ is the propitiation for the whole world. What we have to decide is what it means that Christ is the propitiation for the whole world. I have tried to show that it cannot mean that He is the propitiation for all the peaple in the whole world unless one takes the view that all the people in the whole world are saved.
So what we now have to decide is what the text actually means. The word kosmos does not usually mean 'everyone.' Its natual meaning is 'world.' For example, look at Acts 17:24. "God who made the world and everything in it....' Here, and in many other places, kosmos means 'Planet Earth.' Elsewhere, as I have shown, it means the world as it lies under Satan. It has a whole variety of meanings, and it is the job of the exegete to explain what the true meaning is. I will come to that in due course, but I have a great pile of things to do over the next few days so it won't be that quickly.
Actually Martin you have missed the intent of that verse.
By reading 1Jn 2:1-2 and letting the words inform you rather than reading your view into the text it will clear up your confusion.
1Jn 2:1 My little children, I am writing these things to you so that you may not sin. And if anyone sins, we have an Advocate with the Father, Jesus Christ the righteous;
1Jn 2:2 and
He Himself is the
propitiation G2434 for our sins; and not for ours only, but also for
those of the whole world.
Propitiation is a noun in this verse and as such it is telling us what Christ is. He is the only means of appeasing God the Father.
Is there any other means by which man can be saved? Jesus says there is not in Jn 14:6 "I am the way, and the truth, and the life; no one comes to the Father but through Me."
John is telling us in 1Jn 2:2 there is not. He is telling us that Christ is the only means for those that believe and the only means by which anyone
{the whole world} can be saved.
We see this again in 1Jn_4:10 where John is writing to believers and pointing out that Christ is the only means by which their sins were covered.
As you correctly said the word "world" can mean different things. But it seems you have ignored the context and instead have jumped to other verses to find support for your understanding of the word.
Christ being the propitiation for the whole world does not mean that all will be saved. That is something that you are reading into the text. What it does means is that all can be saved through faith in Him.