Behold, how great a love the Father has bestowed on us, that we should be called children of God! For this cause the world doesn't know us, because it didn't know him.

 There are two pictures, one from the Old Testament and one from the New, which aptly and vividly set out this relationship. In the Old Testament there is the covenant idea. Israel is the covenant people of God. That is to say, God on his own initiative had made a special approach to Israel; he was to be uniquely their God, and they were to be uniquely his people. As an integral part of the covenant God gave to Israel his law, and it was on the keeping of that law that the covenant relationship depended. 