If you misunderstand the purpose of the X-ray as to say the X-ray is the doctor, You will not be healed.In the same way, it is equally true, If you misunderstand the purpose of the law as to say- the law is the saviour, you will not be saved.The purpose of the law is to state that you are a sinner by letter(outwardly) and that you are a sinner by spirit(inwardly) and therefore salvation remains permanently a gift of God's grace.