“And Jesus [God’s Son] came and spoke to them, saying, ‘All authority has been given to Me in heaven and on earth’” (Matthew 28:18)

If you think about it, someone or something has caused you to (wrongly) think that you yourself are the director of your life, that you will decide how it’s going to be. What it boils down to is that you would be claiming to be God: you would be your own authority.
“Authority” may be defined as the right to say so, and the power to enforce what is said! A simple illustration of this would be the speed-limit sign (the right to say so), and the police-officer who enforces the speed-limit sign (that’s in his power to do so).
So, who has the right to say so and the power to enforce issues of life and death? Only 2 possibilities exist: either the Judeo-Christian God (the God of the Bible) has the right and the power; or fallible sinful beings do. The problem with the latter, however, is that mankind (or spirits) can’t decide the course of everyone’s life – – they are either too weak, too flawed, or too deceptive in leading millions astray.
In simple language, you don’t have power to overcome death or to decide the afterlife – – only a perfect God can do that because:
1. He alone is God.
2. He has the right to say so (being the Creator and controller of this universe and mankind).
And 3. He alone has the power to give or take life by whatever means He chooses. Can you really decide when and how you will die? Can you really decide what will happen thereafter?

You can cling and clamor for your own religious authority/authorities, but in the end, you better be right! Eternal consequences await you; you know!