13 When Joshua was by Jericho, he lifted up his eyes and looked, and behold, a man was standing before him with his drawn sword in his hand. And Joshua went to him and said to him, “Are you for us, or for our adversaries?” 14 And he said, “No; but I am the commander of the army of the Lord. Now I have come.” And Joshua fell on his face to the earth and worshiped and said to him, “What does my lord say to his servant?” 15 And the commander of the Lord's army said to Joshua, “Take off your sandals from your feet, for the place where you are standing is holy.” And Joshua did so.
Joshua 5:13-15 (English Standard Version)
In the Book of Joshua, the LORD has commissioned Joshua to be the leader of the Hebrews, to lead them into the Promised Land. God told Moses he would not be allowed in the Promised Land, so when Moses died, Joshua was now the leader. God told Joshua. The above verses come right before the Hebrews are going to conquer Jericho, a super-city with a fortified wall. The wall down comes down, without being touched! Joshua fully trusted God. He understood that he was not in charge, but the LORD was. He encountered the commander of the army of the LORD, and Joshua knew that he was to be respected. The LORD is not on anyone's side. It is US who has to choose to be on His.
To be on God's side, it is necessary to know what being on Satan's side means. In my blog www.bibleanalysis.org I have briefly covered the difference between God and Satan.
Being on God's side is not a bed of roses. It is full of trials but a person becomes righteous and holy. On the other hand, being on Satan's side is essentially selling the soul for a temporary victory.
Make no mistake, there may be billions of people who do the work of Satan on earth.