Why does God let us hurt? Why does He bring us people or animals to love when He knows we’re going to lose them?
Maybe because we don’t love people or animals simply because we’re going to have them forever. We love them because loving them changes us. It makes us better, kinder, healthier, more real. Even if people leave us, or animals die, loving them still makes us better.
So we keep loving. Even though we’re going to lose. Because loving teaches us and changes us, and that’s what we’re here to do. We’re here to become better lovers and to learn how to be loved. So when we get to heaven, we’ll be prepared for the place where everyone loves each other perfectly.