According to Luther, the purpose of every vocation is to love and serve one’s neighbor… For Luther, vocation was far more than economic activity, including also our callings in our families, the church, and the culture as a whole. Each of these vocations calls us to particular neighbors whom we are to love and serve.
Furthermore, God himself, in his providential care for his whole creation, is working through our human vocations. God gives us our daily bread by means of the farmer, the miller, and the baker. He protects us by means of lawful magistrates. He creates and cares for new human beings by means of fathers and mothers. He proclaims his Word and administers his sacraments by means of pastors. He creates beauty by means of artists and musicians.
To use Aristotelian terms, loving one’s neighbor means to treat other human beings, particularly those we meet in our vocations, as intrinsic, not instrumental goods; that is, we see them as being valuable in themselves, and not just for how we can use them.