Good question... Let’s try to answer it.
In Paul’s letter to the Ephesians we read that while good works don’t earn us God’s acceptance, He, nevertheless, intends believer's to perform them - or "walk in them."
"For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them."
(Ephesians 2:10, ESV)
This makes sense when we remind ourselves that the Bible paints a holistic picture of the believer’s life. The Christian is a person whose life is entirely and continually shaped and governed by the grace of God. And this is where good works come into play. It is because every aspect of the believer’s life is lived within the sphere of God’s grace that he/she will perform good works through the gracious enabling of God.
The reason for good works in the believer's life becomes even more clear when we remember that Ephesians 2:10 wasn’t written as an isolated statement – but rather part of a broader explanation about the effect of God’s grace in the lives of His people.
Consider again what Paul writes in Ephesians 2:10, but this time noting what he first says about grace in the two prior verses:
"For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast. For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them."
(Ephesians 2:8-10, ESV)
The Apostle is telling us that God, in his grace, is the source of every aspect of our salvation from start to finish, including the good works that we perform. In fact, v.10 tells us that “our” good works aren’t really “ours” at all. They are His. He prepared them beforehand. He gets the credit for them.
As we’ve already mentioned, good works don’t save us but they are proof that God has saved us by grace... and is saving us by grace... and that’s why good works are important.