The GICI notes the Scripture references that identify the body of believers as a building, a nation, and a priesthood: pretty dignified, I’d say. This section also describes why valid baptism is not repeated:
4. Further, baptism is the sacrament by which its recipients are incorporated into the Church and are built up together in the Spirit into a house where God lives, (Ephesians 2:22) into a holy nation and a royal priesthood. (1 Peter 2:9) Baptism is a sacramental bond of unity linking all who have been signed by it. (Unitatis Redintegratio 22) Because of that unchangeable effect (given expression in the Latin liturgy by the anointing of the baptized person with chrism in the presence of God’s people), the rite of baptism is held in highest honor by all Christians. Once it has been validly celebrated, even if by Christians with whom we are not in full communion, it may never lawfully be repeated.