First, I think perhaps he is revealing that, as a whole, God’s people will never be wiped out. Despite fierce persecution in the first 4 centuries of Christianity, we’re a billion+ strong now.
But I also think there’s another aspect of this.
Jesus alludes to it in Matthew 10:28: “Don’t be afraid of those who want to kill your body; they cannot touch your soul. “
Jesus is like, ‘Guns and swords? Don’t even worry about those. They can only kill the part of you that’s going to die anyways.’
I think the real weapons that our enemy has forged against us are greed and lust and self-pity and hate and fear; among many others.
But the reason these weapons are not supposed to affect us is because Jesus makes us immune. His joy is stronger than depression. His peace can’t even be understood, much less defeated.
It’s when our life is “hidden with Christ” (Colossians 3:3) that we become completely untouchable to the weapons of the enemy.
We live in the cross fire. Bullets of selfish thoughts and actions are always heading our way. People living without Jesus are riddled with holes from these attacks. I think a lot of Christians are, too - when they drag their world-proof vest behind them in the mud instead of wearing it.
Paul is pretty clear about this in Romans 13:13-14: “Don’t participate in the darkness of wild parties and drunkenness, or in sexual promiscuity and immoral living, or in quarreling and jealousy. Instead, clothe yourself with the presence of the Lord Jesus Christ. And don’t let yourself think about ways to indulge your evil desires.”
Only in Jesus are you immune to the weapons of the devils warfare. Stay in him. Don’t try to do it yourself. There are no medals of honor to be won in heaven, because Jesus already won them.