Humans love to make monuments. Whether it's the Arch of Titus in Rome, the Arc de Triomphe in Paris, or the battlefields of the Civil War in the United States, we're fond of setting up memorials and statues to remind us of great historical events.
When God told the children of Israel to build a monument in Joshua 4, it was much less elaborate—just twelve rocks from the bottom of the Jordan River. And what did it commemorate? God parting the Jordan and bringing the Israelites into the Promised Land (see vv. 20-24).
Have you ever forgotten some great scriptural truth, and when you hear it again you say, "Oh man, that's been there this whole time? How did I forget?" The Lord understands our tendency to forget. That's why He commanded the Israelites to set up stones—so they would be reminded of His great acts of love and mercy. It would make the next generation curious as well: "What are those rocks doing there?" And then they would be told the story and their faith would in turn be strengthened.
The spot where Israel set up this memorial was at a place called Gilgal, which became their base of operations in the Promised Land. That meant any time they would return from a battle feeling discouraged, all they would have to do was look at the twelve stones. "Look at those rocks. They came from the bottom of that river when the waters rolled back and we walked over on dry land. Remember what God has done."
And here's an interesting note: Gilgal can be translated rolling or a circle, meaning this was quite possibly the site of an ancient pagan altar where stones were set up in a circle for the ritual worship of other gods. So the Israelites in a sense reclaimed this place for Yahweh, the true and living God.
As beautiful as that is, the bad news is that eventually Gilgal lost its spiritual significance. Later on, it reverted back to a place of pagan worship while the children of Israel occupied the land, and God pronounced judgment on it because of that (see Hosea 4:15; Amos 4:4; 5:5).
So what's the lesson? If you don't cultivate a garden of remembering what the Lord has done for you, weeds are going to grow up. Make it a goal of yours to set up personal memorial stones, some way of remembering what God has done in your life, whether that's through journaling or creating something more visual. It will give you perspective and help you remember spiritual milestones that you can then tell the next generation about.
The very last verse of Joshua 4 explains that the stones at Gilgal were set up so "that [Israel] may fear the Lord [their] God forever" (v. 24). That didn't happen, unfortunately. That's the sad history of the nation. But the good news is that history doesn't have to be yours.