I'll hand that one over to the Got Questions website, as they've done a good job of explaining it:
Question: "How can there be subordination / hierarchy in the Trinity?"
Answer: It may sound strange to speak of subordination within the
Trinity. After all, Jesus and the Father are “one” (
John 10:30). Subordination makes us think of a lower rank or a subservient position. To understand how there can be subordination in the Trinity, it is important to understand that there are different types of subordination. The biblical or orthodox view of the triune nature of God acknowledges an
economic subordination in the Trinity but denies the heretical view of an
ontological subordination.
What does this mean? Simply that all three Persons of the
Godhead are equal in nature. God the Father, Jesus the Son, and the Holy Spirit all have the same divine nature and divine attributes. Contrary to the teaching of many cults, there is no
ontological subordination (no difference in the
nature of the three Persons of the Godhead). This means that the Trinity is not comprised of greater and lesser gods; rather, there is one God existing eternally in three co-equal Persons.
What the Bible does teach is an economic (or relational) subordination within the Trinity. The three Persons of the triune Godhead voluntarily submit to each other respecting the roles They perform in creation and salvation. So, the Father sent the Son into the world (
1 John 4:10). These roles are never reversed in Scripture: the Son never sends the Father. Likewise, the Holy Spirit is sent by Jesus and “proceeds from the Father” to testify of Christ (
John 14:26;
15:26). And Jesus perfectly submitted His will to the Father’s (
Luke 22:42;
Hebrews 10:7).
Economic or relational subordination is simply a term to describe the relationship that exists among God the Father, God the Son, and God the Holy Spirit. Essentially, economic subordination within the Trinity refers to what God
does while ontological subordination refers to who God
is.
Biblically, all three Persons of the Trinity have the same essence, nature, and glory, but each One has different roles or activities when it comes to how God relates to the world. For example, 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 that we see the Father, Son, and Spirit perform are the result of the eternal relationship that exists among the Persons of the Trinity.
The issue of subordination within the Trinity is nuanced, and the distinction between ontological and economic subordination is fine indeed. Theologians within Christian orthodoxy continue to debate the limits of subordination and its relation to the Incarnation of Christ. Such discussions are profitable as we study the Scriptures and think through the truth about the nature of God.
www.gotquestions.org/subordination-Trinity.html
