Today in the U.S. we celebrate Memorial Day by remembering soldiers who died while serving in the military.  Remembering is important.  Without setting aside time to reflect, we lose our moorings, our history.  The same is true of our spiritual history.  The Psalms are filled with injunctions to remember what God has done and how he has worked in mighty ways.  When important events occurred in the Old Testament, people often constructed memorials:

So Joshua called together the twelve men he had appointed from the Israelites, one from each tribe, and said to them, “Go over before the ark of the LORD your God into the middle of the Jordan. Each of you is to take up a stone on his shoulder, according to the number of the tribes of the Israelites, to serve as a sign among you. In the future, when your children ask you, ‘What do these stones mean?’ tell them that the flow of the Jordan was cut off before the ark of the covenant of the LORD. When it crossed the Jordan, the waters of the Jordan were cut off. These stones are to be a memorial to the people of Israel forever.” (Joshua 4:4-7).

Today we still need to have memorials for God:  tangible objects or rituals that help us remember what he has done.  We can form habits and patterns for our lives that help us remember God.