1 John 2:2 says Christ is the propitiation or means of salvation for the whole world, and does not say Christ propitiated the sins of the elect or of the whole world. Thus John 1:29 does not say Christ took away (past tense) the sins of the world, but takes away the sin of the world, one sinner of the world at a time when he or her is transferred into Christ.
You need to get the two very different views in your understanding before objecting to either one of them. All scripture supports the view Christ laid down His life as a ransom for all, but only those transferred into Christ are reconciled. That is why we have the ministry of reconciliation.
Just a small correction, perhaps.
John’s use of propitiation is not a “means” to salvation, rather John is stating that the actual blood is the propitiation.
There is a difference in the consideration if one uses “means of” rather than “is.”
Of course, the scholars would point out that a more literal translation of 1 John 2:2 is “He propitiated sin, ours, and all humanity.”
Which is directly contrary to the typical view of some on the B.B.