Ephesians 6: 12 For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms.
It is reasonable to say that if you are in a fight you have identified and are able to see the enemy. Ephesians 6 is telling us that in the spiritual realm the exact opposite is true – the enemy is neither physical nor visible. Hence the call to equip ourselves with battle gear which are not physical but spiritual – the armor of God – truth, righteousness, the gospel of peace, the shield of faith, the helmet of salvation, and the sword of the Spirit which is the Word of God. “And pray in the Spirit on all occasions with all kinds of prayers and requests.” God has fully provided the necessary uniform for us but it is up to us to dress ourselves, otherwise we will not stand a chance against the devil’s schemes.
Above and beyond all this we learn from the Word of God that there are times when God deems some battles to be such an affront to him or that he has a specific outcome in mind that he intervenes to dismantle the enemy’s plans himself.
In the first instance we read that when the Assyrian King Sennacherib decided to invade Israel, the angel of the Lord showed up in answer to Hezekiah’s prayers and Sennacherib’s army was dead by daybreak. (2 Kings 19) In the second instance God revealed himself to Joshua in a different way. There was a battle going on but Joshua learned that it was not just between his army and that of the enemy but that the Lord God had a vested interest in the outcome of this battle. So he sent his commander to take charge. (Joshua 5). God does fight battles for his people or to defend his own name.
“When the mission is mine, I send my own captain to lead. That ensures success. All the planning that men do means nothing unless I lead. I set my host against the host of the enemy. The battle is mine not the believer’s. The believer’s place is to trust me completely for the outcome. Do not think for a moment that when Satan masses demons against you, you can fight by yourself. It takes the captain of the Lord’s host to war against them. I am the Almighty God and I do not leave my children to fight alone. The battle is mine and I will not fail you.”