God is dead, as Nietzsche said. What will take God’s place?
What is everywhere present, the most powerful thing ever, and which created us and sustains us? Nature or the universe. Nature is also sacred.
All mystical experiences are experiences of a union with nature. Yes, it often is imagined as a person. But this a psychological glitch in humans, not an aspect of reality. In order to understand what is not like us, we make it like us. The fancy word for this is anthropomorphism.
But another replacement for God is fate. Fate is that which is inevitable. It is that which is beyond our control. Instead of saying “God willing,” we should say “fate willing” we do this or that.
Although not a very good moral example, God was a moral example to emulate. This can be replaced with better and more real examples of the sages, such as the Buddha, Laozi, Confucius, Socrates, Zeno, and Epicurus. Even Jesus might be used as an example if we undeify him.