Answer
Logic, mathematics, and philosophy all utilize axioms. In those contexts, axioms are concepts that must be accepted but cannot be proven or disproven. A simple example is that numbers are equal to themselves: x = x. Another is the law of non-contradiction, which states that mutually exclusive statements cannot both be true in the same sense at the same time.
No system can avoid using axioms. Fundamental axioms are uniquely beyond the normal rules of logic. Instead, we define logic in relation to those ideas and their applications. Even attempting to prove or disprove an axiom requires the use of other axioms. Denying axiomatic principles makes rational thought impossible. They “must” be believed because without them communication breaks down, and nothing can be understood.
God’s existence—the “why” of God’s being—is the axiom of our reality. God simply is because, if He were not, there wouldn’t be anything. When we ask, “Why does God exist?” or “What is the reason God exists?” we’re speaking of something that doesn’t apply to Him. Such questions attempt to apply cause-and-effect to a Being who is prior to and the source of all causes and reasons.
This means there is no reason for God’s existence. In fact, there can’t be one. Logically, His existence comes before all reasons. Asking “why” something exists implies it could possibly not exist. “Why” implies a cause leading to a result. Without the “why,” that thing would not occur. God, who has always existed and always will «Before the mountains were brought forth, or ever thou hadst formed the earth and the world, Even from everlasting to everlasting, thou art God. », (Psalm 90:2), has no “why.” He must exist. When Moses asked the Lord to identify Himself, God simply said, “I AM” (Exodus 3:13-14). Jesus reiterated the concept of “I am” concerning His own eternal existence «Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am. », (John 8:58). The most straightforward explanation of God’s nature is that He is the Only Necessary Thing: the ultimate foundation of all reality.
Critics may argue that stating, “God simply exists” is evasive, not a response. Nevertheless, it is as legitimate as any other axiom. In the Christian perspective, God brought into being everything except Himself (Genesis 1:1;John 1:3). When we inquire, “Why does 1 = 1?” or “Why can’t there be square circles?” or similar inquiries about logical and mathematical axioms, we can only offer that explanation: they simply are. Reality—let alone reason—would not exist if those axioms were false. We cannot provide a rationale for why axioms are accurate. We can only acknowledge that they are accurate and that they must be.
Likewise, for anything to have existence, there must be an ever-present, uncaused, necessary “something” that is not the consequence of anything else. There is no explanation for God’s existence; instead, He is the ultimate reason for every other aspect of reality. God’s existence is appropriately axiomatic: He exists simply because He must.