The Bible teaches that God alone created the universe. It also gives us a number of reasons as to why He did it.

1. He Created It for Himself

One of the reasons that God created the universe was for His own self.

The LORD has made everything for its purpose, even the wicked for the day of trouble (Pro 16:4).

Paul wrote.

For from him and through him and to him are all things. To him be the glory forever! Amen. (Rom 11:36).

For by him all things were created: things in heaven and on earth, visible and invisible, whether thrones or powers or rulers or authorities; all things were created by him and for him (Col 1:16).

2. Creation Was by His Own Will

God created all things for His own will and pleasure.

He predestined us to adoption as sons through Jesus Christ to himself, according to the kind intention of his will (Eph 1:5).

John wrote.

You are worthy, our Lord and God, to receive glory and honor and power, for you created all things, and by your will they were created and have their being (Rev 4:11).

3. He Created the Universe for His Own Glory

The universe was also created for the glory of God. The prophet Isaiah wrote.

Everyone who is called by my name, whom I created for my glory, whom I formed and made (Isa 43:7).

The psalmist declared.

The heavens declare the glory of God; the skies proclaim the work of his hands (Psa 19:1).

4. He Created the Universe to Make Known His Power and Wisdom

God made all things to make known His power and wisdom

And to make plain to everyone the administration of this mystery, which for ages past was kept hidden in God, who created all things. His intent was that now, through the church, the manifold wisdom of God should be made known to the rulers and authorities in the heavenly realms (Eph 3:9-10).

Summary

Scripture tells us why God created the universe. First it was for his for His Person—not for humanity. Creation was also according to His will. There was no one else who advised Him. Also He created everything for His own glory—not the glory of any other. The purpose was to make known His power and wisdom. Consequently the Bible teaches there is no reason, outside of God Himself, for His creative acts.