1.The Persons of the Trinity Have Different Primary Functions in Relating to the World. When Scripture discusses the way in which God relates to the world, both in creation and in redemption, the persons of the Trinity are said to have different functions or primary activities. Sometimes this has been called the “economy of the Trinity,” using economy in an old sense meaning “ordering of activities.” (In this sense, people used to speak of the “economy of a household” or “home economics,” meaning not just the financial affairs of a household, but all of the “ordering of activities” within the household.) The “economy of the Trinity” means the different ways the three persons act as they relate to the world and (as we shall see in the next section) to each other for all eternity.
We see these different functions in the work of creation. God the Father spoke the creative words to bring the universe into being. But it was God the Son, the eternal Word of God, who carried out these creative decrees. “All things were made through him, and without him was not anything made that was made” (John 1:3). Moreover, “in him all things were created, in heaven and on earth, visible and invisible, whether thrones or dominions or principalities or authorities—all things were created through him and for him” (Col. 1:16; see also Ps. 33:6, 9; 1 Cor. 8:6; Heb. 1:2). The Holy Spirit was active as well in a different way, in “moving” or “hovering” over the face of the waters (Gen. 1:2), apparently sustaining and manifesting God’s immediate presence in his creation (cf. Ps. 33:6, where “breath” should perhaps be translated “Spirit”; see also Ps. 139:7).
In the work of redemption there are also distinct functions. God the Father planned redemption and sent his Son into the world (John 3:16; Gal. 4:4; Eph. 1:9–10). The Son obeyed the Father and accomplished redemption for us (John 6:38; Heb. 10:5–7; et al.). God the Father did not come and die for our sins, nor did God the Holy Spirit. That was the particular work of the Son. Then, after Jesus ascended back into heaven, the Holy Spirit was sent by the Father and the Son to apply redemption to us. Jesus speaks of “the Holy Spirit, whom the Father will send in my name” (John 14:26), but also says that he himself will send the Holy Spirit, for he says, “If I go, I will send him to you” (John 16:7), and he speaks of a time “when the Counselor comes, whom I shall send to you from the Father, even the Spirit of truth” (John 15:26). It is especially the role of the Holy Spirit to give us regeneration or new spiritual life (John 3:5–8), to sanctify us (Rom. 8:13; 15:16; 1 Peter 1:2), and to empower us for service (Acts 1:8; 1 Cor. 12:7–11). In general, the work of the Holy Spirit seems to be to bring to completion the work that has been planned by God the Father and begun by God the Son. (See chapter 30, on the work of the Holy Spirit.)
So we may say that the role of the Father in creation and redemption has been to plan and direct and send the Son and Holy Spirit. This is not surprising, for it shows that the Father and the Son relate to one another as a father and son relate to one another in a human family: the father directs and has authority over the son, and the son obeys and is responsive to the directions of the father. The Holy Spirit is obedient to the directives of both the Father and the Son.
Thus, while the persons of the Trinity are equal in all their attributes, they nonetheless differ in their relationships to the creation. The Son and Holy Spirit are equal in deity to God the Father, but they are subordinate in their roles.
Moreover, these differences in role are not temporary but will last forever: Paul tells us that even after the final judgment, when the “last enemy,” that is, death, is destroyed and when all things are put under Christ’s feet, “then the Son himself will also be subjected to him who put all things under him, that God may be everything to every one” (1 Cor. 15:28).
Grudem, W. A. (2004). Systematic theology: an introduction to biblical doctrine (pp. 248–255). Leicester, England; Grand Rapids, MI: Inter-Varsity Press; Zondervan Pub. House.