Why is there something rather than nothing? This is a popular question that is usually answered sophically. A better answer involves aseity, or God’s self-existence. The proof text in scripture for His self-existence is:

God said to Moses, “I am who I am.” And he said, “Say this to the people of Israel: ‘I am has sent me to you.’” Exodus 3:14 English Standard Version (ESV)

Theologian, author, and pastor R. C. Sproul says the following concerning the concept of aseity and its alternative:

Aseity is the view that God is entirely self-sufficient and not dependent or contingent upon anything else. In other words, He is the eternal, independent, and personal cause of the universe.

Some thinkers appeal to self-creation to account for reality while denying God’s existence. As self-creation is illogical, others attack the concept of causality itself. An appeal to the philosophy of David Hume is often made to prove that uncaused effects do exist.

…[However,] Hume did not deny that causes exist, he just believed we cannot determine what they are. The law of causality still holds true: “Every effect must have a cause.”

For anything to exist, an uncaused something, or someone, must exist. It is not an uncaused effect that must exist, for there can be no such thing. Self-creation, an uncaused effect, may be an illogical contradiction, but a self-existent, “uncaused cause” is not.

This “uncaused cause” must have the power of being within itself—it must exist in and of itself. This cause must be eternal, for that which does not exist cannot later bring itself into existence. Moreover, this cause must be personal for an impersonal one could not create personal beings. Only a personal, self-existent God can answer the question: “Why is there something rather than nothing?”

American-Dutch Reformed theologian, Louis Berkhof, in his work Systematic Theology, says the following about God’s self-existence:

…The answer to the question, whether the Absolute of philosophy can be identified with the God of theology, depends on the conception one has of the Absolute.

…When the Absolute is defined as the First Cause of all existing things, or as the ultimate ground of all reality, or as the one self-existent Being, [the Absolute] can be considered as identical with the God of theology. He is the Infinite One, who does not exist in any necessary relations, because He is self-sufficient, but at the same time can freely enter into various relations with His creation as a whole and with His creatures. While [God’s] incommunicable attributes emphasize the absolute Being of God, [His] communicable attributes stress the fact that He enters into various relations with His creatures.

…As the self-existent God, He is not only independent in Himself, but also causes everything to depend on Him. This self-existence of God finds expression in the name Jehovah. It is only as the self-existent and independent One that God can give the assurance that He will remain eternally the same in relation to His people.

Additional indications of it are found in the assertion in John 5:26, “For as the Father hath life in Himself, even so gave He to the Son also to have life in Himself”; in the declaration that He is independent of all things and that all things exist only through Him, Ps. 94:8 ff.; Isa. 40:18 ff.; Acts 7:25; and in statements implying that He is independent in His thought, Rom. 11:33-34, and in His will, Dan. 4:35; Rom. 9:19; Eph. 1:5; Rev. 4:11. in His power, Ps. 115:3, and in His counsel, Ps. 33:11.

Thus, with Sproul, we conclude:

…Only a self-existent, personal God for whom non-existence is impossible can adequately explain the design, causality, and personality evident in the universe.

In other words, God’s aseity explains why there is something rather than nothing.

R.C. Sproul: Before the Beginning: The Aseity of God, YouTube, Ligonier Ministries, This message is from Ligonier’s 2004 National Conference, A Portrait of God