The Scriptures reveal that the Father, Son, and Holy Spirit cannot be understood apart from their unity.  To be in a relationship with God is to enter a relationship with all that God is an all that God does.  Our union with God is union of concern for all God has created.  We are initiated into that union at Baptism, and at that moment we no longer exist in isolation but are joined with the communion of saints; we become members of a body that we dare to name the Body of Christ.  Every time we invoke the Trinitarian God we affirm this truth.