For it is not those who hear the law who are righteous in God's sight, but it is those who obey the law who will be declared righteous. (NIV)
For it is not merely hearing the Law [read] that makes one righteous before God, but it is the doers of the Law who will be held guiltless and acquitted and justified. (AMP)
(For not the hearers of the law are just before God, but the doers of the law shall be justified. (KJV)