The children of Ephraim mentioned in Psalm 78 failed the Lord, And they failed their fellow Israelites when their help was badly needed (vv.9-11).
What a tragedy it is when people fail in their warfare. Jesus warned us in Luke 9:62 about those who look back and do not fulfil the will of God. If we are looking back, we cannot plow ahead. And if we look back, we cannot fight as we ought. Yes there is a spiritual battle going on, and we need every soldier. But The children of Ephraim were unfaithful and turned back in the days of battle.
Something was wrong with their walk (v.10). God wanted them to walk in His law that He might help them win the battle, but they would not obey Him. They also forgot what God had done for them (v.11). Can you imagine forgetting a miracle? If a miracle took place in your life today, you would call a press conference! And you talk about it until the day the Lord called you home. Think of the miracle God did for His people. But they forgot what He had done for them. They turned against the law of God.
Unfaithfulness is common in people. But not so with God. Faithfulness is part of His character. This truth ought to encourage you if you know the Lord. Be faithful in your walk with God. Remember His works and be a faithful soldier in your battle for Him.