Now therefore ye are no more strangers and foreigners, but fellowcitizens with the saints, and of the household of God (Ephesians 2:19)
Last night I accompanied the youth on a temple trip to do baptisms for the dead. The temple president spoke with them briefly before we got started. He compared baptism with a naturalization ceremony for those who desire to become U.S. citizens. I immediately thought of the scripture above from Ephesians. I think it's a good analogy. He talked about how the naturalization ceremony requires that we know certain things and commit to certain things, and that we are then accepted as members of the community -- the celestial community, for baptism. (And, of course, there is the implication of necessary authority.)
As I look at the Ephesians verse, I note also that it includes both "fellowcitizens with the saints" and "of the household of God". I believe "of the household" means "part of the family". I think these are both similar and distinct concepts. We become "the seed of Christ" at baptism, but we are not sealed into the family until we have received the temple covenants, and had them sealed upon us by the Holy Spirit of promise. This is a process of progression indicated in the scriptures by various relational terms describing us as slaves or servants to God, or children, or friends.