Winning battles typically involves superior weapons, larger forces, or a better strategy.  But when God is Commander-in-Chief, all rules of war are thrown out.  Consider how various people participated in winning this particular battle (Ex. 17:8-16): Joshua fought, Moses prayed, Aaron and Hur assisted, and the LORD God, Yahweh Nissi, was the rallying point - the banner lifted high that carried them to victory.
    As long as Moses kept his eyes focused on God and his arms lifted to him, the Israelites prevailed.  But as he grew tired and his arms sagged, the enemy advanced.  Aaron and Hur saw Moses' problem, helped him sit, and then physically assisted Moses to keep his arms raised over the battlefield.
    How true that is in our lives as well.  When we are focused on God, recalling that he is our banner, our victory, and our only hope, we are able to overcome the obstacles and conflicts in this life.  But when we tire and allow fatigue and weariness of spirit to distract us from spending time with God in worship and prayer, the enemy advances and overtakes us.  If we insist on solitary worship and obedience, we will fail.  We need other believers to come alongside and assist us to persevere.
    Let the examples of Aaron and Hur remind you of an important asset when it comes to your faith walk. Look for opportunities where you can join with others in prayer, encouragement, and worship.  Identify those fellow believers who can come alongside you and hold up your hands.
    Begin your day as Joshua did, fighting in God's name.  Raise your hands to God in constant prayer as Moses did.  And look for those Aarons and Hurs who can assist you throughout the day to persevere, keeping your eyes on the Lord, your banner lifted high.