But they're sooooooo OLD Testament

Dear Grace answers a question asked by kids for generations:

Dear Grace, My son and I were discussing the importance of the Ten Commandments and how they are to be used as a guide. He says they are part of the Old Testament and therefore we need not focus that much on them. His attitude towards them is that they are just a lot of "Do Nots." Can you help me explain why God gave us these commandments and why they are still important for us today?