In 1 Kings 2, we have the fascinating story of Elijah’s rapture into Heaven I think it could be helpful if we looked at this passage for some of the reasons why the third chapter of Hebrews treats the land of Canaan as a type, first, of the whole world, and second, of Heaven itself.
The key is the dividing of the river Jordan. You should recall that the first time the Jordan was divided was when Joshua brought the people over, right near Jericho. Their invasion of Canaan through a divided Jordan typified the Christian church beginning the process of discipling all the nations.
Now just before Elijah was caught up into Heaven, he came to Jericho. Immediately after this, he came to the Jordan, and caused it to divide so that he and Elisha could cross over (1 Kings 2:8). This they did, heading east out of the promised land. This indicated that Elijah was about to enter Canaan, following Joshua, and what he entered was Heaven.
But then Elisha does it again on the return trip. A double spirit from Elijah rests upon him, and he causes the Jordan to divide again, going west into Canaan, just as Joshua had done centuries before (1 Kings 2:14). Elisha’s ministry is much broader, more internationally connected, than Elijah’s had been. Elisha entered Canaan as a new Joshua — and so Canaan also represents all the nations of men (Heb. 3:14-4:1).
Centuries after this, John the Baptist appears, in the same place, dressed exactly as Elijah had been dressed (and probably Elisha also), and preached a baptism of repentance.
But this new Elijah is not dividing the water so that the people of Israel could stay dry. Now he is getting the people wet (with the water of that same Jordan) so that the people would be divided. The New Testament is very clear that the baptism of John established a clear division or boundary within the Jewish people (Luke 7:30).
Before he divided the water for the people. Now he divides the people with the water.
Canaan then is a type of a type. The promised land meant a promised world, and a promised world meant at promised Heaven.
Good observation. What had been a division that was fundamentally social (including the children) was now fundamentally ethical (mature judgment). New Covenant baptism cuts not the flesh but the heart. It concerns the Spirit, which is why circumcision, and paedobaptism, mean nothing. If John was baptizing babies in the Jordan, his baptism would have created a new fleshly division.