God

God is the main subject of the Bible. Although it teaches about many other subjects along the way, everything Scripture includes can ultimately be traced to God’s will to save fallen humanity in a way that shows his glory conspicuously and makes him known intimately.

The Trinity

From beginning to end, the Bible is the story of the one true God, who is Father, Son, and Spirit (Deuteronomy 6; Matt. 28:18–20; John 16–17). As we read the Bible, we discover that in the fullness of time the Father sent forth his Son and Holy Spirit (John 14–16; Gal. 4:4–6) for salvation and revelation. The Son and the Spirit are of the same essence as the Father and have coexisted with him in perfect unity for all eternity. Thus the God attested to in Scripture is the one God who shows himself always to have been three persons in one being.

God’s Attributes

The Bible describes God as one, yet he bears multiple attributes, which are intrinsic, eternal qualities constituting who he is. God is so perfectly one that his attributes all interpenetrate and mutually imply each other. Thus calling him “good” does not imply that he meets some external standard of “goodness”; he himself is goodness, and displays it perfectly. The same can be said of all his perfections. But while they cannot be separated (as if God could be holy but not loving, or transcendent but not immanent), they can be considered individually.

Theologians often classify God’s attributes as either incommunicable or communicable. God’s incommunicable attributes are those he does not share or “communicate” to others, such as his self-existence, eternity, immutability, spirituality, infinity, omniscience, and so forth. These often relate to the uniqueness of God as compared to humans. For example, God is self-existent, while humans are creatures. God is eternal; humans are time bound. God is immutable; humans change.

  God’s communicable attributes are intrinsic to God’s very nature as well, yet they can and should be displayed in humans; these include his love, goodness, mercy, grace, patience, truthfulness, integrity, moral holiness, righteousness, and so forth. Through union with Christ these attributes are shared with his people, so the church is to be increasingly marked by holiness, love, truth, and the other communicable attributes.

In Exodus, God himself recites some of these attributes in a list (Ex. 34:6–7) that seems to be an explication of his own revealed name, which he states twice at the beginning: “The Lord, the Lord.” He then names a number of his perfections (“a God merciful and gracious, slow to anger, and abounding in steadfast love and faithfulness”), followed by the characteristic actions he takes based on who he is (“keeping steadfast love for thousands, forgiving iniquity and transgression and sin”), and concluding with a counterbalancing statement of his abiding righteousness (“but who will by no means clear the guilty”).

God’s Self-Sufficiency and Glory

The Christian doctrine of God’s perfections preserves the dynamic of passages like this, which display who he is for our salvation, while tracing those actions back into the eternal life of who he essentially is and has been from eternity. To put it hypothetically, because of how God acts when he creates and redeems us, we know how God would have been even if he had never done these outward actions. So Christians confess that God has absolute self-sufficiency (aseity). Nothing he does is done out of need or greed, as if he could gain or lack anything. This self-sufficiency also determines how we talk about God’s relation to time and space, which do not limit him in any way, nor is he shut out from any part of them. God’s moral perfections are the ones clearest in Scripture and most characteristic of his identity: goodness, love, mercy, holiness, righteousness, and jealousy. All of the divine perfections considered together shine forth a radiance summarized by the word glory.

This same unity of all his perfections is experienced by God himself as blessedness, or perfect happiness. The doxology in 1 Timothy 6:15–16 is a good example of how these perfections are praised together: God is “blessed” and the “only Sovereign,” exalted over all powers (“King of kings and Lord of lords”), the only source and ground of everlasting life (“who alone has immortality”), and inaccessible to creaturely scrutiny (“who dwells in unapproachable light, whom no one has ever seen or can see”). Glory and eternal lordship are ascribed to him.

Our Salvation

Throughout the OT, God indicated in various ways that he himself would be the salvation of his people (“he has become my salvation”; Ex. 15:2). When the Father sent the Son to become incarnate and the Holy Spirit to indwell the redeemed, he fulfilled his promise in a surprising way. “God with us” meant the Father sending the Son and the Spirit, who are more than created agents—they are fully God. The incarnation and Pentecost are not merely the next mighty acts of God in a sequence but are the central events of salvation history that make known the Trinity’s presence among us.

These two persons within the unity of God had not previously been revealed with such clarity and distinctness; in the OT they were glimpsed, hinted at, or adumbrated (literally, “shadowed forth”). But once they appeared as themselves in salvation history, they had to be recognized as having always existed. The fact that they were sent, though being fully equal with the Father, can be traced to the fact that, within the divine life of the living God, the Son and the Spirit stand eternally in a relationship of being from the Father (as opposed to holding a status lower than the Father’s, as the heresy of Arianism taught). These eternal processions of the Son and the Holy Spirit are the basis of their missions into the history of salvation.

The Doctrine of the Trinity

The result of understanding how the Son and the Spirit stand in relation to the Father is the doctrine of the Trinity: the one God eternally exists as three persons—the Father, the Son, and the Holy Spirit. This formula, combining the three persons in this order, was given directly by the Lord Jesus (Matt. 28:19), though the key words normally used to explain the doctrine do not themselves appear in Scripture: person, essence, relation, or even Trinity. What matters, of course, is that the ideas they point to are biblical. As long as that is established, we are free to use the enormously helpful terms we have inherited from ancient Christian usage. The doctrine of the Trinity can be broken down into a handful of truth claims, each of which can be demonstrated from Scripture: there is one God; the Father is God, as are the Son and the Spirit; the Father is not the Son, nor the Son the Spirit, nor the Spirit the Father; and so on.

Adoption and the Trinity

The most important immediate implication of God’s existence as Father, Son, and Holy Spirit lies in the understanding of salvation. Christian salvation is adoption into the family of God, an event in which the eternally begotten Son of God brings those whom he is not ashamed to call brothers, through union with him, into his filial relationship with the Father. This happens through the atonement in Christ and the indwelling Spirit of adoption in the redeemed. It is no surprise that salvation becomes clearer and deeper when understood in light of the Trinity.

  Remember that God did not clearly reveal his triunity in advance of sending the Son or the Holy Spirit; the revelation of the Son and Spirit was directly tied to the event of their coming in person to accomplish and apply salvation. The revelation of this interpersonal depth in God, in other words, was bundled with redemption. The doctrine of the Trinity is thus the result of a thorough understanding of the nature of the gospel, drawing out the implications of what the gospel is and what it entails about the God who is its source. Thus the doctrine of the Trinity answers the question of who God is according to the good news of salvation in Christ. It is the Christian doctrine of God.