God is infinite, meaning He cannot be defined, limited, or described exhaustively or adequately, but only known truly. ‘Canst thou by searching find out God?” “The finite cannot grasp the infinite” is an old maxim. God gives no definition of Himself neither does the Bible but only reveals Himself to us so we can know Him and have a relationship with Him. It’s not whether you can define Him, but whether you know Him that counts. Describing God won’t save your soul but trusting and believing in Him will.
When we define God it’s like putting Him in a box and making Him one-dimensional (the man upstairs, the Great Spirit in the sky, Father Time, the Cosmic Killjoy, the Celestial Policeman, our Father Figure, the Force, etc). The only useful description of God I’ve heard of is by St. Anselm of Canterbury who said, God, is that perfect Being above or beyond which cannot be conceived or imagined; whatever is greater to be than not to be He is.
God is the Creator and the universe is part of creation, not part of God who created it and is separate from it or transcendent. Something logically cannot be both created and the Creator. The universe had a beginning; the Big Bang and is not eternal; God did not!
Also, God must be immutable and eternal as well as immaterial to be God for God is not in flux but changes not and is not the slave of time or anything in the time-space continuum. Anything subject to change cannot be God. Being the Creator of time, He is not bound by it or limited by it but all things in the time-space continuum had a beginning.
But God who is eternal with no beginning or cause but is that First Cause that is a necessary being. Something has to be necessary or nothing would exist. God's name means “I CAUSE TO BE.” His name also means: “I AM,” or that He is self-existent and dependent or contingent upon no one or nothing unlike us. Soli Deo Gloria!