Trinitarianism refers to the study of the triune God. It often includes such topics as rational arguments for the existence of God, the attributes of God, the Names of God, the trinity, and the decree or plan of God.
It needs to be said up front that the Bible nowhere argues for the existence of God in the way envisioned in these “proofs.” The overwhelming orientation of the Biblical writers is to assume that God exists and move on from there. Also, the strength of these arguments has been variously debated; some people find them helpful and generally convincing, especially when taken together, while others are not the least bit convinced. It is doubtful whether there is any necessary logical fault involved in denying any one of their premises or assertions since in many cases opponents are simply beginning with a different set of axioms. Further, there are many variations (i.e., more than one cosmological argument) of the arguments listed here. One should consult a textbook on the philosophy of religion for further discussion.8 Also, one should note that these arguments have been criticized by more than atheists. Many Christians have wondered out loud about their efficacy, value, soundness, and importance. The following is simply an introduction.
The argument from creation, or otherwise known as the cosmological argument states, in its most basic form, that everything we know in creation or in the universe has a cause (i.e., is contingent). But there cannot be an infinite regress of causes. Therefore, the universe itself has an uncaused cause and this Cause is God. In one form or another this argument has been advanced by Plato, Aristotle, Aquinas, Leibniz and in recent years by Richard Swinburne. One potential defeater of this argument is the denial that one must look outside creation for a cause; creation might simply have always existed. But some take issue with this rebuttal arguing that such a response is in reality a copout since it does not explain why the universe of created, apparently contingent beings continues to exist. Also, it seems to be question-begging to ex cathedra postulate an infinite series of causes when such an argument is logically trivial and according to many philosophers and physicists, absurd. An infinite series of causes is an intellectual copout, they argue, and violates the principle of sufficient reason.
The argument from design, or otherwise known as the teleological argument observes the harmony, order, and design of things within creation. It then argues that such design and order implies purpose and, therefore, there must be an intelligent Designer and that Designer must be God. This argument too has been advanced since Greek philosophy and was propounded by Aquinas as his Fifth Way, William Paley, and also by Swinburne in recent times. One potential defeater of this argument is the apparent randomness of certain things and events in creation and the apparent lack of design. The problem of the quantity of evil would fit in here as well. Proponents of the design argument often suggest that there do appear to be random events, and so on, but this still does not detract from the overwhelming sense of design we experience. If design were not so, it is doubtful that human beings could or would have survived even this long.
Anslem’s argument9 from being, or otherwise referred to as the ontological argument, claims that God is that “than which nothing greater can be thought.” Since existence is a necessary property of the most perfect being, he must actually exist, since if he did not, he would not be the most perfect being one could think of. One potential defeater of this argument is the claim that it entails the notion of God in its premises. It, therefore, assumes what it is trying to prove. “It begs the question,” as some would say.
The argument from morality argues from the fact of morality, not the existence of what appear to be varied moralities. It states that the fact of conscience and morality indicate that there must be a moral Law-Giver. One potential defeater of this argument is the claim that morality is an evolutionary phenomenon and one does not need to postulate God in order to account for its existence. Others attempt as well to argue that there are many different moralities, a fact they claim does not lead one to the conviction that there is just one God, as theism argues. Proponents of the argument from morality point out that the evolutionist cannot have it both ways. The mechanism for evolution is generally taken to be some form of “survival of the fittest.” If, then, morality were a evolutionary phenomenon, one would not expect human beings to care for the aged, to help the sick, to create, fund, and advance hospitals and medical research. But we do, and we find ourselves with a sense of guilt when we do otherwise. Also, it is by no means certain that there are many different moralities among human beings on the planet. In fact, the overwhelming data from sociologists is that in terms of basic morality about murder, stealing, lying, etc. humans are for the most part very similar. This does not mean that lying is sometimes honored; it means that it cannot be practiced consistently and universally in any one culture without that culture ceasing to function.
The attributes of God refer to those qualities or properties that set him apart as God and by which we recognize him as such. Theologians have tended to distinguish his attributes in terms of those that he alone possesses and those which he shares in a derivative and finite sense with his creation. Thus they refer to “Absolute and Relative,” “Immanent and Transitive,” and the most popular division among Reformed theologians, “Incommunicable and Communicable” attributes. Generally listed in the Incommunicable list are: Self -existence, immutability, infinity, and unity. Attributes listed under the heading of communicable include: spirituality, intellectual, and moral attributes, as well as attributes of sovereignty and power.
God has revealed himself in many ways throughout history, now recorded for us in Scripture—a living, inspired record of his disclosures about who he is, his purposes, plan, character and will. On many occasions he has given us a name by which he has unveiled his nature and by which we are subsequently to understand him. Some of these names include: Yahweh (the self-existent one)10; Yahweh Shalom (Yahweh is peace); Yahweh Maccaddeshem (Yahweh your sanctifier); Yahweh Raah (Yahweh is my shepherd); Yahweh Shammah (Yahweh who is present); Yahweh Rapha (Yahweh who heals); Yahweh Elohim (Yahweh, the mighty one); Adonai (Lord or Master); Elohim (The mighty or majestic one); El Olam (The mighty one, eternal); El Elyon (The most high mighty one); El Roi (The mighty one who sees); El Shaddai (Almighty God); Yeshua (Jesus; God saves); Christos (Christ; Messiah, Anointed one); Kurios (Lord); Soter (Savior), Abba (Father), and Theos (God).
The doctrine of the trinity is the affirmation based on the evidence of scripture that there is one God who exists eternally in three distinguishable persons, i.e., the Father, the Son, and the Holy Spirit. A specific way of speaking about this phenomenon is to say that God is: one in essence/substance (homoousios), three in subsistence. The prominent contribution of the OT to trinitarianism, while providing what some consider to be evidence of the divinity of the Son and the Spirit, is to repeatedly affirm the unity of God, both numerically and qualitatively. This unity is developed in the NT, however, in light of the coming and teaching of Christ, and shown to be more complex than had hitherto been known or understood. In the NT all three (i.e., the Father, Son and Spirit) are said to be divine, to do the works of God, and to be worshipped as God. The Father is clearly divine in the NT. The Son is deity (John 1:1; Titus 2:13), yet constantly distinguishes himself from the Father and the Spirit. And the Spirit is said to be God (Matt 28:19-20; Acts 5:3-5) and to be distinguished from the Father and the Son. Thus there is no room in the Biblical portrait for three gods (tritheism) or one God who manifests himself in three different modes (modalism). The Biblical portrait of God is that he is Trinitarian.
The best statement of the “plan” of God or as is sometimes referred to as the decree of God, is that found in the Westminster Shorter Catechism: “The decrees of God are his eternal purpose, according to the counsel of his will, whereby, for his own glory, he hath foreordained whatsoever comes to pass” (Q.7). This doctrine can be seen in several places including most notably, Romans 9 and Ephesians 1:11: “in whom we also were called, having been foreordained according to the plan of him who works out all things in conformity with the counsel of his will.”
This is to be distinguished from God’s will as understood from his commands and prohibitions which are clearly laid out in the Decalogue, expanded and applied by the prophets and brought to a Christocentric focus in the NT. The fall of man, then, was in the decree of God, but the command “not to eat the fruit,” was clearly specified by God and He is thus not the author of sin in any way. Nothing more clearly teaches us that human beings have been endowed with a measure of genuine, responsible choice than sin. Thus there is a mysterious relationship between what has happened in history (i.e., the outworking of the decree) and the moral imperatives we find in Scripture. This mystery can be seen most clearly in the quintessential event of the cross and its portrayal in sacred scripture (cf. Acts 2:22-24; 1 Peter 1:20). The end result, of course, is a revelation of the glory of God (John 12:23-27)!
Jesus taught that his death was not an “accident of history,” but rather according to the foreordained or decreed plan of God. In Luke 22:22 he says: “the son of man goes as it has been determined” (horismenon). Peter says, regarding the crucifixion and peoples’ involvement in it, that Jesus was handed over to them by “God’s set purpose and foreknowledge” (horismene boule kaiprognosei tou theou). Yet in neither of these cases are the people and their actions minimized or the moral and spiritual consequences trivialized. Jesus says “woe” to the person who betrays him and Peter referred to the men as “wicked” (Acts 2:22-24). In sum, the early church implicated Herod, Pontius Pilate, the Jews, and Gentiles in this awful deed, claiming that they had done what “God’s hand and will determined beforehand should happen” (he cheir sou kai he boule sou proorisen genesthai). Again, see Acts 2:22-24. These texts tend to confirm the Augustian/Calvinistic doctrine that the decree of God is not identical with his foreknowledge; he knows the future because he has decreed whatsoever comes to pass.
The discussion of the order of the decrees has theological importance, but cannot be entertained at length here. Those who argue that God decreed first to create, then to permit the fall, then to save some and condemn others, to provide a redeemer, etc. are referred to as infralapsarians and would constitute most Calvinists. Those who argue that God first decreed to save the elect and condemn the non-elect, and then to create the elect and non-elect, then to permit the fall and finally to provide a redeemer, are referred to as supralapsarians.
8 I would recommend C. Stephen Evans, Philosophy of Religion, Contours of Christian Philosophy, ed. C. S. Evans (Downers Grove, IL: InterVarsity, 1982), 31-76.
9 Anslem was not really arguing per se for the existence of God from the idea of “being.” In his Proslogion (AD 1079) he was simply meditating and praising God for his greatness. Part of his greatness is that he necessarily exists, at least as far as Anselm is concerned.
10 The difficulties in establishing the proper meaning of Yahweh are many and varied. Attempts to discover its meaning along the lines of comparative philology are tenuous at best, but so also with an examination of the verbal root. Its usage in Exodus 3:14 has generally been argued to suggest something along the line of God’s self-existence or at least the One who had been with the nation of Israel since the patriarchs.