There's a higher power and it's not worshiping a master in the sky. It's understanding the mental realm. Example, Jesus didn't say eternal life in John 3:16. He talked about Aionic Life, which is that timeless mental realm, which the religions before advocated as well. It's old technology. You have to read the original Greek to see it. They reframed or mistranslated after the Greek.
Remember Pythagoras?
They didn't talk about it to us, but Pythagoras was into that kind of mental stuff. He had his own mystery "school". Topics similar to esotericism and hermeticism. Buddhists are into it, that meditation for enlightenment stuff. It's the real mechanics... vs the distorted fairy tale of believing there's not only a single-sex human man in the sky but they're also your master and you're only going to matter after you die.
These are all death cults (but, not as you expect. hint: it's not actual death)
Rebirth and resurrection is during your life, not after. Thats the mistake. People didn't understand it because it's esoteric, elusive. That's the ancient stuff. Its initiation. Why we pantomime initiation in the fraternity, masonry, etc. It's a weak version. They used to feed people strong drugs that took them to the Aionic realm, while guiding them in the imagery to cause them to realize certain things. And religion sprang out of people trying to make sense of that, or, from the people who didnt understand that at all... or from the people looking for a new control system to gain power over others.
The Buddhists said fuck that. Drugs are dangerous. We can do it with mental focus alone. And they did. But that's more of a rare experience to achieve.
Shamans give peyote, mushrooms, auyasca, to achieve this. Amanita, Ibogane. There's many ways. But all are guided. The guidance imagery matters. Baptism in the water, causing near death is another way.
We all trip when we die, a funny feature of our circuitry.
Eleusis was a religion for 1500+ years, and people walked for 9 days. Once there they were given a cup of psychedelic beer, and told a story that set the image in their minds that led to extreme unity of the mind, revelation, and rebirth of your thinking. Cicero, the Greek, explained "he wishes he did it earlier", and "it was the single most important thing for humanity". What exactly it invoked, unsure. But it revolves around death and resurrection imagery deep enough in your brain that it evokes something that resets you and makes you more human, a better self, a rebirth during this life.
It's fascinating.
Impossible to exactly say. And it depends on the initiation's guidance.
Here are some that stick with people