“When you are about to go into battle, the priest shall come forward and address the army. He shall say: “Hear, O Israel, today you are going into battle against your enemies. Do not be fainthearted or afraid; do not be terrified or give way to panic before them. For the LORD your God is the one who goes with you to fight for you against your enemies to give you victory.” 
{Ok, that part sounds good…}
The officers shall say to the army: “Has anyone built a new house and not dedicated it? Let him go home, or he may die in battle and someone else may dedicate it. Has anyone planted a vineyard and not begun to enjoy it? Let him go home, or he may die in battle and someone else enjoy it. Has anyone become pledged to a woman and not married her? Let him go home, or he may die in battle and someone else marry her.” Then the officers shall add, “Is any man afraid or fainthearted? Let him go home so that his brothers will not become disheartened too.””
(Deut 20:2-8 NIV)
So the army is going into battle, and the high priest comes and tells them don’t be afraid or weak, because God is fighting for you! So everyone would have confidence, right?
But then the officers are supposed to add a few other options.
If you have built a new house, you better go back home, because not being afraid and having a great victory and having God fight for us does not mean some of us are not going to die.
If you haven’t enjoyed your new vineyard, go back home, because God is fighting for us and will give us victory, and some of us may die.
If you haven’t delighted yourself in your soon-to-be wife of your youth, go back home and do that, because God is fighting against our enemies and will give us victory, and some of us may die.
that is SO UPSIDE DOWN from what our human understanding would think! 
But doesn’t this keep with everything else we see about God? What He calls victory is so much more complicated and richer than what we would call victory. And He doesn’t want anybody fighting that doesn’t want to. Nobody is getting forced to go to war. And they don’t have to go before a conscientious objector panel to prove that he should not go to war. Can you imagine that happening during Vietnam?
I know there is a war, your honor, but I just planted a grapevine, and I have to wait for its grapes. After I harvest my grapes and make wine and let it age and then drink some, then I’ll come fight.
Even in a war God didn’t FORCE His people, and I don’t see any curse or bitterness from God towards the cowards or new vine-planters either!
Be FREE!