For a long time I believed in “destiny” because things that happened in my life were just too weird for me to believe they were random. But it caused me an issue because destiny or even karma require an overseer or god or puppet master, whatever you choose to call the ephemeral guider. And I just couldn’t align that in my mind. Then I discovered the chaos theory. It explained everything without an invisible being conducting things. Life isn’t really random, it is a series of events driven by other events that can happen way outside of your knowledge, but that drive the things that happen in your life. And every choice you make, no matter how inconsequential it may seem to you has repercussions in other peoples lives that you probably never know about.
The “chaos theory” is at its base an explanation for the univers, but the univers is us. This solved all the issues for me and was actually the time in my life when I went from defining myself as an Agnostic to an Atheist. Works for me!