The next dual relationship that constitutes a “holy order” according to the Table of Duties in Luther’s SMALL CATECHISM is that of parents and children:
Fathers, do not provoke your children to wrath, but bring them up in the training and admonition of the Lord. Ephesians 6:4.
Children, obey your parents in the Lord, for this is right. “Honor your father and mother,” which is the first commandment with promise: “that it may be well with you and you may live long on the earth.” Ephesians 6:1-3.
So in what sense is being a child a vocation? What are the proper duties of children? How can they love and serve their neighbors in that particular calling?