The actual devotional begins at 1:30.
While we're in Ephesians, I would also point to this:
For we are God’s handiwork, created in Christ Jesus to do good works, which God prepared in advance for us to do. -- Ephesians 2
Paul delivers this as a one-two punch with "not by works," and I think both ideas should always be taught together.
There is a difference between Isaiah's "righteous works" and Paul's "good works." Paul discusses the difference explicitly in Romans.
A "righteous work" is an attempt to put God into our debt and to obligate God to our salvation. "Righteous work" is trying to get God into a position where we can say, "God, I did work for you, so you owe me salvation....a worker deserves his wage!"
That is different from "good work," which is work that God had already assigned to His believers before creation and without regard to anything we might think to do on our own. A "good work" is God's to-do list. We don't get to God's "good works" until after we have become His servants.
That's why:
So you also, when you have done all that you were commanded, say, 'We are unworthy servants; we have only done what was our duty. '” Luke 17
Everything we do as faithful servants is already on God's to-do list of "good work," bidden in us by the Holy Spirit. There's not really any such thing as a "supererogatory" work.
