I'm always thinking that same kind of thing but today I gained a new perspective. When a non-christian says that, I guess, it could actually be true. God is on all of our sides, we are all in the same boat together. Does he call all people his children? I'm not sure about that either way. But I'm sure He's still on their side and sure he desires their... well I guess I'm not entirely sure what he desires for us. I guess I'm sure he desires their happiness, he did create this world, and he did create us, and though temporal, must have purpose. Heaven sounds much more glorious, and glorifying, so I don't think his only purpose for the earth was to glorify Himself. All right I'm heading down rabbit holes I know there's no end to so I'll stop now.

If it had not been for the Lord we wouldn't exist at all. It's a strange thing to think about that God created us but he also made us independent so he still has to save us from ourselves and his other creations. Mind bending.