Imagine that you were a smoker. You know that your health is important, but you also find it hard to quit. God shows us what is wrong to stop us from harming ourselves and those around us. He shows us what is right to help us live out our full potential as his children. That's what salvation is.
Morality is a bunch of rules, nothing more.
Right and wrong isn't just an arbitrary set of rules. Right and wrong defines our relationship with God and the people around us. When we fail to live by our morals, we aren't right before God and have no peace with others. The problem is, it's not possible to completely live up to God's perfect and absolute standard on our own. That's why God came as Jesus to restore our relationship with him.