Ephesians 2 is filled with the good news of grace for both our justification and sanctification. The chapter begins by describing our natural condition—trapped in sin and by sin, rebelling against God to pursue our own ends on the one hand and suffering as the victims of those ends on the other—and then moves to how God loved us and rescued us by His grace, His sheer goodwill.
The first half of the chapter focuses on what happened in the past—how God took pity on us and rescued His people, delivering us from our sin and His wrath. But the story doesn't end there. As Peter O'Brien notes, salvation has already been described by Paul as relief from something negative: "a resurrection from the dead, a liberation from slavery, and a rescue from condemnation." The chapter continues to verse 10, which centers on how God's deliverance means we are created anew for lives of righteousness.
The theme of Ephesians 2:8-9 is clear: grace. This theme was already mentioned in 1:4, when Paul mentioned how God set His mind on delivering us before the foundations of the world, but what was then more of an undercurrent now becomes the main point. We are saved by His grace, not by anything we have done.
When you start to think that you're absolved of all your sins not by virtue of your brainpower or your goodness or your good works, but by something entirely outside yourself, the unearned goodwill, benevolence, and favor of a God who decided to take an interest in your case and to invest heavily on your behalf at His expense—that's humbling. At the same time, it should give you confidence that the God who saves you even when you are least worthy of being saved is capable of love on a scale that you can't imagine. To bring up our efforts as a means of gaining God's favor distorts our understanding of the God we worship.
But if our efforts don't gain God's favor, what are they for, and how (since we're still very much prone to sin) do we go about living? Paul now moves in 2:10 to focus on "good works." It is tempting at first glance to think that verses 8 and 9 are about grace and verse 10 is about works, as though grace sets up an account with God, and works put the money in the bank. But this would be to miss something very important that we easily neglect: God is the source of our entire salvation, from start to finish. Or, as one commentator puts it, "It is grace all the way." So what does that mean, exactly?
Now that we've discussed how good works don't lead to salvation, the most perplexing verse might be the one that says that God prepared good works for us beforehand. Notice how God-centered Ephesians 2:10 is. It may be about our doing works, but it is still very centered on God. In the Greek, the first word in the sentence is "his," which is an unusual placement and puts the emphasis squarely on God. We are "his workmanship." We "are created [by God] in Christ Jesus" for good works. These good works were those "which God prepared beforehand." Clearly, works are important to Paul, but his emphasis here is on God's bringing them about within us.
We must always hold verse 10 together with verses 8-9. The Bible paints a holistic picture of the believer as one whose life is continually lived in grace that bears fruit, fruit that is used by God to bless others.
What does that look like? If our works are "prepared beforehand," what do we do? Paul says we "walk in them," the same phrase he used to describe our life in sin. Good works become as much a part of our lives as our own pursuits were before. In other words, at the most basic level, we show up. We abide in the vine of Jesus (John 15:4). We walk by the Spirit (Gal. 5:16-25), obeying what God asks of our energy, money, and commitment even when it seems absurd or unfair; giving to the poor; surrendering our independence and pride; and forgiving the wrongs done to us. Make no mistake—what seems to be our part is hard and demanding. But the crucial thing to remember in the hard times is that it is not actually our part, but God's kindness, that will end up allowing us to walk at all, transforming our desires, motivations, and behaviors.
"Walking in good works" means we do our best not to mess it up. Yet we will mess it up, and when we do, grace picks us up again. It's like the old Rich Mullins lyric: "If I stand, let me stand on the promise that you will see me through, and if I can't, let me fall on the grace that first brought me to you."
Above all else, and before any discussion of what we should do, we must understand deeply in our bones who we are: the workmanship of God. You are His project, and He has only just begun His good work in you (Phil. 1:6-7).