Ecclesiastes 3:18-21

I said in my heart with regard to the children of man that God is testing them that they may see that they themselves are but beasts. For what happens to the children of man and what happens to the beasts is the same; as one dies, so dies the other. They all have the same breath, and man has no advantage over the beasts, for all is vanity. All go to one place. All are from the dust, and to dust all return. Who knows whether the spirit of man goes upward and the spirit of the beast goes down into the earth?