Arguments for the existence of God

Arugments for the existence of God involve carefully crafted reasoning with the hope that an individual will come to the conclusion that God exists.

Also known as proofs for God's existence, these arguments have not always come with full acceptance. Those opposed to natural theology claim that God's existence cannot be proven by human reason or the natural world. Viewpoints vary, but responses tend to conclude that God can only be known by supernatural revelation or Scripture alone. Karl Barth is a classic example of this as he believed that God is exclusively revealed in Jesus Christ, and Jesus is only revealed in the Bible. Proponents of natural theology vary as well, but most conclude that the existence of God can be known through human reason although it is not salvific (not a saving knowledge of God). Thomas Aquinas is characteristic of this view, holding to the understanding that the created world reflects aspects of its creator that are apparent to all. Nonetheless, arguments for the existence of God have been formed throughout church history and continue to be used today, namely in the area of apologetics.

Kalam Cosmological Argument
The aim of this argument is to show that the universe had a beginning in the finite past. The argument battles against the existence of an infinite, temporal regress of past events which implies a universe that has infinitely existed. This argument implies the existence of a First Cause.

The form of the argument is:
 * (1) Whatever begins to exist has a cause.
 * (2) The universe began to exist.
 * (3) Therefore, the universe has a cause.

Thomistic Cosmological Argument

 * (1) What we observe in this universe is contingent (i.e. dependent, or conditional)
 * (2) A sequence of causally related contingent things cannot be infinite
 * (3) The sequence of causally dependent contingent things must be finite
 * Conclusion: There must be a first cause in the sequence of contingent causes

Leibnizian Cosmological Argument
The argument comes from a German polymath, Gottfriend Wilhelm Leibniz. Leibniz wrote, &quot;The first question which should rightly be asked is this: why is there something rather than nothing?&quot;

The argument runs as follows:
 * (1) Every existing thing has an explanation of its existence, either in the necessity of its own nature or in an external cause.
 * (2) If the universe has an explanation of its existence, that explanation is God.
 * (3) The universe is an existing thing.
 * (4) Therefore the explanation of the universe is God.

Some atheists object to premise 2 in that God does not have to be the explanation, but that the universe can be what is called a necessary being (one which exists of its own nature and have no external cause). This was a suggestion of David Hume who demanded, &quot;Why may not the material universe be the neccesarily existent being?&quot; (Dialogues Concerning Natural Religion, part 9). The Kalam Cosmological Argument is helpful. If Hume (and other atheists) is right in saying that the universe is a necessary being/thing, then this implies that the universe is eternal. This is exactly what the Kalam argument seeks to disprove. Thus, the Kalam is a valuable supplement to the Leibnizian argument.

Teleological Argument
Probably the most popular argument for God's existence is the teleological argument. Derived from the Greek word telos, which refers to purpose or end, this argument hinges on the idea that the world gives evidence of being designed, and concludes that a divine designer must be posited to account for the orderly world we encounter. Although the teleological argument dates at least as far back as Plato, it is perhaps most memorable today from the work of William Paley (1743-1805), in his Natural Theology (1802). Recently, the teleological argument has gained renewed interest as a core element of the theory of Intelligent Design and the related efforts to reconcile science and faith.

Although there are variations, the basic argument goes something like this:


 * 1) X is too complex to have occurred randomly or naturally.
 * 2) Therefore, X must have been created by an intelligent being, Y.
 * 3) God is that intelligent being.
 * 4) Therefore, God exists.

Objections to the teleological argument
Regarding the first and second premise -- The first (and therefore second) premise assumes that one can infer the existence of intelligent design merely by examining an object. The teleological argument assumes that because life is complex, it must have been designed. This is an example of non-sequitur logic. Life or objects are described as, â€œorderlyâ€ or â€œorderedâ€. This implies that an intelligent designer has ordered them. In reality a system can be non-random or ordered simply because it is following impersonal physical processes, for example diamonds or snowflakes.

Regarding the third premise -- Some argue that even if the first and second premises are accepted, the implied designer (Y) might be an unknown force or mere demiurge, not God as God is commonly understood. It is argued in defence that the outside force through which Y came into being might then be explained as a more powerful being resulting in either an omnipotent being or infinte regression.

Critics often argue that the teleological argument would apply to the designer, arguing any designer must be at least as complex and purposeful as the designed object. This, they say, would create the absurdity of an infinite series of designers. However, the counter-argument of an &quot;undesigned designer,&quot; akin to Aristotle's uncaused causer, is common.

the Wikipedia article Teleological argument

Ontological Argument
&quot;The ontological argument attempts to prove Godâ€™s existence through abstract reasoning alone. The argument is entirely a priori, i.e. it involves no empirical evidence at all. Rather, the argument begins with an explication of the concept of God, and seeks to demonstrate that God exists on the basis of that concept alone.

&quot;The argument is ingenious. It has the appearance of a linguistic trick, but it is a difficult task to say precisely what, if anything, is wrong with it. All forms of the argument make some association between three concepts: the concepts of God, of perfection, and of existence. Very roughly, they state that perfection is a part of the concept of God, and that perfection entails existence, and so that the concept of God entails Godâ€™s existence.&quot;

The ontological argument was first formulated by Anselm of Canterbury (1033-1109), one of the great medieval philosopher-theologians, in his Proslogium, Chapter 2. Anselmâ€™s ontological argument rests on the identification of God as â€œthat than which no greater can be conceivedâ€. Once it is understood that God is that of which no greater can be conceived, Anselm suggests, it becomes evident that God must exist.

Descartes' ontological argument
We have the idea of an infinitely perfect Being. Since we are finite, and everything around us is finite, the idea of an infinitely perfect Being could not have originated with us or with the nature around us. Therefore the idea of an infinitely perfect Being must have come from such a being - God. 

Resources

 * God, Are you There? Five Reasons God Exists and Three Reasons it Makes a Difference, by William Lane Craig (from the RZIM Critical Questions Booklet Series)
 * Does God Exist? The Debate between Theists and Atheists, by J.P. Moreland (theist) and Kai Nielsen (atheist). Prometheus Books, 1993.