'That Which Is Good' in the Bible

Then has that which is good become death to me? Let it not be! But sin, that it might appear to be sin, working death in me by that which is good; in order that sin might become exceedingly sinful by the commandment.

For I know that in me (that is, in my flesh) dwells no good thing. For to will is present with me, but how to perform that which is good I do not find.