I accept that, occasionally, my systems will fail. My data will be lost. No recovery will be possible, and the damage will be permanent and lasting. I do not hope to succeed in those times, but expect to be scarred. I will fail.
Given that I will fail, I'd like to understand how I fail. I'd like to understand why I fail. I'd like to measure how often I fail, how short I fall of success, and the root causes of my failure. I'd like to know when failure is about to happen or is happening.
By writing down what I do, I know how to fail. I can write down what I do when I don't fail, too. I can write while I do, and I can read what I wrote to do it again. I can let somebody else read and do what I have done.
I can expect to fail sometimes. I can expect to not fail sometimes. I expect failures based on causes, not based on self-blame. I expect to not fail most of the time, and only fail at certain times when something has caused me to fail.
I can fail less in the future. My actions today can change how I fail in the future. I can plan to fail, or intentionally fail, or sometimes fail less. I act intentionally.
I haven't failed in a while. The last time I failed, I looked at why I failed and I did what was necessary to try to recover and fail less.
This is how SRE works. This isn't overconfidence; this is fault-tolerance. It's not easy, but it works.
To respond to your point about faith, I have plenty of faith, just not hope that my faith will be able to prevent me from failing.
And finally, try Nix sometime. It's pretty cool.