But you understand you don't have 15 billion years plus or minus several billion?
We estimate the earth to be stable enough for life at 3.8 billion plus or minus several hunderd millions years ago. Then, if you accept evolutionary theory, another 2.8 billion years is needed to explain the rest of evolution.
So you're window is down to a billion years or so.
Still a long time but remember what needs to occur.
Amino acids need to form. Life uses 20 of these acids and it has been shown that 13 of them can occur naturally. Let's assume that holds true for the remaining seven.
So we have these 20 amino acids. They must all form in the same place.
They must then form into 2,000 different proteins containing strings of 300 amino acids each for the simple bacterium to exist.
The baceterium must then survive, reproduce and evolve.
It is irrational to believe that this could have happened without direction.
You may have noted in a link in my last message that one amino acid has been identified in stellar gas, independent of earths age. All of this doesnt have to occur on Earth.
Life could have begun here or on any of the millions or billions of earth like planets with varying ages. Thats one of the points in the other link in my last message to you. The odds of any specific person winning the lottery may be 15 million to one, but someone wins it. Earth may be one of the winners.
You dont know the odds of biogenesis. Because of the unknowns and the interdependent dynamics, no one knows the odds, except God of course :^). So you have no way of claiming that this is irrational with credibility. Thats only what you want it to be.
I sometimes wonder why the people who cant accept that a simple replicating life form was produced from the universe over billions of years insist that something as great as God came into being from, whatever ;^)
Im going to be unavailable for a day or so. Best regards