We cannot doubt of our existence while we doubt. The fact that we doubt proves there is a doubter. “I think therefore I am” as Socrates famously said.
In the Old Testament, YHWH says, I AM. I am is a way to say I exist. We also exist because we have free will and can choose independently. While the Universe provides a pool of options, we choose among options before us everyday.
These choices are the only thing that is real in the sense that all physical reality is a simulation or a broadcast via waves interpreted by electrical signals in the brain. Think of a TV picking up waves using an aerial and creating a picture or image. The only real thing that we own is our will. Our will is central to who we are.
Our destiny is determined by our choices. The saying “what you sow is what you reap” is true. We deserve the outcome of our decisions. If I steal something and go to prison, then that demonstrates that I am responsible for my own decisions. No excuses. We are not animals of pure instinct where we decide to do what feels the best. We may CHOOSE to act like that at times, but we have reason that can override instinct. We can look at the big picture and make decisions based on what is the best thing to do which may include sacrifices. If my decisions are mostly bad, then my reality will end up being bad too.
My will is free to choose my destiny, so I try to choose good whenever I can. I choose to align my life with God because he is good. Jesus said, “why call me good, no one is good except God”. He also said, “remove this cup from me, but not MY will, but YOUR will”.
Are we willing to sacrifice our own desired choice to live for ourselves and instead live unto God? Trust me when I say this. ‘God knows best’. Put your trust in him alone.