When the priests carrying the Ark of the Covenant set foot in the Jordan River, the water stopped flowing up north, and piled up until the children of Israel could pass over. When it was time for the priests to move on, the Bible says,

Then the Lord spoke to Joshua, saying, “Command the priests who bear the ark of the Testimony to come up from the Jordan.” Joshua therefore commanded the priests, saying, “Come up from the Jordan.” And it came to pass, when the priests who bore the ark of the covenant of the Lord had come from the midst of the Jordan, and the soles of the priests’ feet touched the dry land, that the waters of the Jordan returned to their place and overflowed all its banks as before (Josh 4:15–18).

That all certainly would have caused Joshua and Israel to know that if they continued to walk in the commandments of the Lord, He would do great things for them, which they also experienced when Joshua asked the Lord to stop the sun and the moon so that Israel could finish a battle.

Just do God’s will, and He will do whatever it takes to make sure that we can do it.