I remember reading about some famous mathematician who tells of how, as a child, he agonised over knowing what a number is. He could not get his head around the concept of a number. He said he failed tests because he'd leave examination papers untouched. While he knew what the answers should be, he couldn't understand why they should be what they were and just sat there in frustration. He quite obviously “got it” at some point but for years it rendered mathematics painful for him because of his lack of understanding.
For me the concept of God’s glory has been similar in nature. The Bible, from front to back speaks of God’s glory. But what does that mean? His glory this. His glory that. What is His glory? For years I couldn’t get it.
At minimum God’s glory means His transcendence over all finite reality. For example, God is
transcendent over life and death. He is not bound by time. God’s glory is everything that makes Him unique. He is perfect. He is self-existent. He is unchanging. He is utterly superior in every aspect. He is the definition of grace and mercy and forgiveness and justice and love. For God IS love. That is the glory of God.