The Three Cultures and Hammurabi's laws

Hammurabi's laws about 4000 years ago still have effect today, such as that all citizens must obey the same laws so everyone is treated equally. I think that is really cool, a law being in effect for that long. Three very important religions: Christianity, Judaism, and Islamic all have their roots in Southwest Asia. Those were all started at very different times though, Christianity in 30 A.D.  Judaism in 200 B.C. and Islam in A.D. 600. If you could make one change in a law for that long what would it be?