That's exactly what God told Abraham about his "sons" or "family", that He would give him children that numbered the stars in the sky and the sand grains in the sea; meaning those that came after him who kept his faith would belong to him. He did not understand what God meant at the time, just like we don't understand some things today. We are but a speck on this earth while we're here and when we leave yet God tells us we are the apple of His eye. He loves us above all others; even our wives, husbands, children.
Nothing grieves Him more than to lose one of His children. We can never comprehend this in earthly terms.