Why the Ten Commandments?

If I tell you what God's law says it's like I'm handing you a mirror. I am not accusing you of having a dirty face, I am just letting you see for yourself. A mirror can show you you have a dirty face, but you can't use a mirror to clean your face.
In the same way, God's Law can only show you how unclean you are by God's standards, but the Law can't make you clean.
Just like rubbing your face with a mirror won't make it clean, trying to live by God's Law will not make you clean in God's eyes.
The BAD news is that if you die with the spiritual equivalent of a "dirty face", you must spend Eternity in the torments of Hell.
BUT stand by for the GOOD news