Why are there two testaments? (Galatians 3)

Have you ever read the Bible from cover to cover? Many people who try it start off enthusiastically until they reach the second half of Exodus where the exciting story shifts into a detailed list of rules and regulations. They find it hard to keep going and they struggle to see the point of it all. If they persevere they are often glad that they did, but the Psalmist's enthusiasm for the Law still seems strange.
The Old Testament, as Christians call it, starts so well with God creating human beings in a wonderful earth. But it soon goes wrong.  Twelve chapters in God makes a wonderful promise to Abraham that all nations of the earth will be blessed through his family. But this family seem unable to be that blessing, no more than any other family would be able.
So God sends Moses, the great Law-giver, and a Law which tells these people how to live. But they can't and don't keep it. That's the story of the Old Testament: a book in which hope never dies but reality keeps striking.
Paul, who wrote Galatians, was once an enthusiast for the Law. He saw it as the word of God and the thing that marked out the people of God. It's provisions like circumcision, food laws and Sabbath keeping, mattered to him. Then he saw Jesus, and the Law paled into insignificance. Paul's hero became Abraham, not the Law-giver but the man who believed God and who was declared to be righteous. Paul announced that God's promise to Abraham was being fulfilled, in those who believed in Jesus. 
So why are there two testaments? To put the question more precisely: why this story that lasts hundreds of years about a law and a group of people who couldn't keep it? Paul's answer, in part, us that the people of God needed a childhood. And as children they needed a list of rules because they weren't yet ready to live in a grown up sort of way. When Jesus came the emphasis went back to faith, through which people could learn what the Law really pointed to.
​More on Sunday .....