1 Thessalonians 4:1, Finally, then, brothers, we ask and urge you in the Lord Jesus, that as you received from us how you ought to walk and to please God, just as you are doing, that you do so more and more.
Paul urges the Thessalonian Christians toward good works for the sake of their neighbour. As Lutherans, we highly value our two kinds of righteousness doctrine: that in passive righteousness, God the Father credits the righteousness of Christ to us by faith; and in active righteousness, we do good works for the sake of our neighbour as the Holy Spirit enables us.
Sometimes, we value our passive righteousness so much that we begin to think we have no active righteousness at all. That is, we say, “I am a poor sinner. I am justified by faith in Christ. There is no good in me because no one is good, as the Scriptures say.” Yes, but now that you are in Christ you are now declared good; therefore, the good works you do for your neighbour is actually you doing it! Christ is in you, yes, but He has not replaced you; you do good works because the Holy Spirit gives you the ability and God thus calls those works good. Your works are pleasing to God because you have faith—because you are in Christ (Hebrews 11:6).
As Christians who are declared righteous in Christ, this means we are actually righteous, not figuratively. Being righteous in Christ is not a theory; it is a reality God has given us through Jesus Christ. This means you do not do anything passively; indeed, you cannot. As a Christian, you can only do good works actively. As actually righteous people, therefore, we are now able to do actual, active good works. Not as though they add to salvation, since they cannot, but merely for the sake of our neighbour who needs our good works.
The Thessalonians were already doing these good works, and Paul encouraged them to continue doing so. Today, we are still doing good works in each of our vocations, whatever they may be; therefore, let us also continue in doing these good works for the sake of our neighbour who needs them.