Answer
The Trinity is one of the most complex concepts in the Bible and nigh inexplicable. We know that God is One (Deuteronomy 6:4), and we know that He exists in Three Persons (Matthew 28:19). It is a paradox, but that is the reality of who God is. Theologians early on in Christian history developed terms and definitions that parse out various aspects of the Trinity. The term “economic Trinity” is one of these.
The term “economic” in “economic Trinity” comes from the Greek word oikonomia, which means, literally, “household management.” The “economy” of a household includes the assigning of roles or jobs within the family. The economy of a home is related to its efficiency. To be clear, oikonomia is never used in reference to the Trinity in Scripture. We refer to the “economic Trinity” when we discuss the unique relationships among the Three Persons of the Trinity.
The economic Trinity is often discussed in conjunction with the “ontological Trinity,” a term that refers to the co-equal nature of the Persons of the Trinity. The term “economic Trinity” focuses on what God does; “ontological Trinity” focuses on who God is. Taken together, these two terms present the paradox of the Trinity: the Father, Son, and Spirit share one nature, but they are different Persons and have different roles. The Trinity is both united and distinct.
That there are distinctions among the three Persons of the Trinity is clear from Scripture. For example, each Person has a slightly different role in the salvation of mankind. Our salvation is based on the Father’s power and love (John 3:16; 10:29), the Son’s death and resurrection (1 John 2:2; Ephesians 2:6), and the Spirit’s regeneration and seal (Ephesians 4:30; Titus 3:5). The different tasks the Father, Son, and Spirit perform help inform our understanding of the economic Trinity.
There is also a voluntary subordination among the Trinity, in that the Father “sent” the Son (John 6:57), the Father and the Son “send” the Spirit (John 15:26), and the Spirit will “speak only what he hears” (John 16:13). The Father, Son, and Holy Spirit are ontologically equal, but they are economically distinct. That is, they have different roles, and those roles involve relationships that can best be described as superordinate and subordinate.
The perfect relationships within the Trinity are difficult to understand, yet they are what all humanity is drawn toward. Perfect love and perfect fellowship exist within the economic Trinity. In His love God draws us into fellowship with Himself. Praise Him for “the grace of the Lord Jesus Christ, and the love of God, and the fellowship of the Holy Spirit” (2 Corinthians 13:14).
Below is the best symbol for the Trinity we are aware of (click to expand):
