If He is the propitiation that is not a verb form but a noun, He is the sacrifice that pleases God. In the LXX the various cognates of that form were particularly used of the provision on the mercy seat, not just a generic concept of atonement.
Jesus is the means of atonement, it is speaking of the type of Sacrifice He performed, not the impact on each person, but the type of provision. It was for all the world. It does not say all of the world benefited from that atonement. It is to Christ's glory that His sacrifice was sufficient for all the world, though we both agree not all the world will be saved.
The term is referencing the OT type, and its fulfillment. He is the atonement provided for all, just as the rites on the Day of Atonement were for all. However, if someone decided to not participate, they didn't benefit.
Except while others were looking at the illustration aspect, I am not referencing that. I am speaking of the actual event, not the application made off it by Jesus.
You said every Israelite looked and was saved from the serpents. It involved repentance. they had to look in faith to the serpent to be healed. And you said that they all did so opposed to just some of them.
How is that possible if you indicated to me before that natural man cannot repent. All of them managed to. How?