I think I answered the question, it is simple statistic, probability of building complex structure achieving meaningful success through thousands of steps and maintaining surviving advantage on most of those steps, I need a great faith in evolutionary process. It works right in your book, have fun.
Thousands of steps in 3.8 billion years worth of evolution, really isn't extra ordinary.
Anyway, sounds like you are completely ignoring the roll of natural selection.
Also seriously understimating the law of big numbers.
Imagine a stable species population of 100 million individuals with a mutation rate of 50. That means every newborn has 50 brand new mutations. About the rate we humans have, btw.
A new generation of 100 million individuals is born at mutation rate 50.
In generation 1 (one), there are already 5 billion mutations
in the field.
Many of these 5 billion will be past on to off spring. Which will add their own 5 billion off course. And pass the accumulation of both to their off spring. And so it goes on.
Every individual that walks around, is literally a fitness test for the genes of that individual.
Statistically and probabilisticly, it really is not a problem at all. In fact, it's an inevitability. The only thing that can stop biological evolution from occuring, is total extinction of all life.