In Joshua 7, after Israel's defeat at Ai due to Achan's sin, a pile of stones was erected over Achan's body as a lasting reminder of the consequences of disobedience. This served as a tangible representation of sin and its repercussions.
A modern proverb says, “Those who do not know history are doomed to repeat it.” God takes sin seriously. Every sin is an act of rebellion against him. It is wise for us to set up stones of remembrance that not only remind us of God’s mercy, but also warn us against falling into sin as they did (cf. 1 Corinthians 10:1-13). A study of Joshua 7:1, 10-26.