Finally then, brothers, we beg and exhort you in the Lord Jesus, that as you received from us how you ought to walk and to please God, that you abound more and more.
And to please God, even as ye do walk ...  Paul here credited them with being in the right way; and the second clause is to make that clear.  One does not say to a Christian, "Do right," except in the sense of growth and perseverance in the course already begun.