I'm thinking of copying answers from my class mate during the final exam.
Why do you want to copy a classmate's answers?
I'm more likely to pass the exam if I copy.
You shouldn't copy exam answers from your classmate because that's cheating, and cheating is immoral. If you want to pass the exam you should study and learn things.
How am I cheating if no one knows I copied their answer? It's called the silent assassin.
Of course it's still cheating if you're not caught, and cheating is wrong. But the chances are high that you will be caught, and you might be expelled.