Wow, that is so convincing! "I would show you, but I'm not going to do that because you hurt my feelings."
So, the first thing is that we do not have the details of how abiogenesis happened.
The question is whether it is possible to get from the types of chemicals we can find readily in the universe to the types of chemicals and reactions we see in life.
Let's start 200 years ago. At that time, there was a distinction made between 'organic' chemistry, which was the chemistry of life, and 'inorganic' chemistry, which was pretty much everything else. At the time, it was thought to be impossible for anything 'inorganic' to produce anything 'organic'. This was an early form of the viewpoint that abiogenesis is impossible.
But, what happened was that urea, an organic chemical, was made from inorganic chemicals in the lab. This was the first inkling that the chemistry of life is not different in principle from the chemistry of everything else. This was the first evidence that abiogenesis might be possible.
Now, this was just the first organic chemical to be artificially made. many more came later and now we know how to produce many simple organic chemicals from inorganic precursors. During this same time, we learned much more about the chemistry of life.
So, we learned that all of life is based on just a few different types of simple chemicals that are put together in a variety of ways. Proteins are made of amino acids, for example. There are thousands of different types of proteins, but only 20 amino acids that made them up. Similarly, DNA and RNA are made from a total of 5 different nucleic bases. There are also a variety of sugars, and some fats (lipids).
So, there became two big questions:
1. Can those simple chemicals arise by natural processes on the early Earth or in the universe at large?
2. Can those simple chemicals spontaneously combine to form the more complicated types of chemicals that we see in living things?
The Urey-Miller experiment addressed the first question with amino acids. Once again, the view at the time was the amino acids were too complicated to form spontaneously from the types of chemicals we knew existed in the universe (ammonia, water, methane, sulfur dioxide, carbon monoxide, etc).
But what was discovered was that even very simple conditions would produce amino acids in abundance. Subsequent experiments showed that a wide variety of initial conditions lead to the formation of the amino acids we see in proteins. This was a surprise and was supporting evidence that abiogenesis might be possible.
In other experiments, it was found that the other simple molecules that are the components of life, like the nucleic bases, could also be formed in a wide variety of situations that would be expected on the early Earth. So, once again, this was evidence that abiogenesis might be possible.
On a different line, the question of whether the simple amino acids and nucleic bases could spontaneously link together to form the more complicated molecules we see in life needed to be addressed. This gets more technical since it has to do with more specific questions. This will be a later post.