In 1953 Miller and Urey did an experiment in an effort to try to create Amino Acids in the lab. Amino Acids are the basic building blocks for life. The experimental apparatus consisted of a vacuum line, high voltage spark electrodes, a condenser, with circulating cool water, a trap to prevent back flow and a flask of boiling water. The sealed tube was later broken to remove reaction products.
They had problem however, the Earth' has an oxidizing atmosphere. It consists of Nitrogen, oxygen, carbon dioxide, and water vapor. The problem for Miller and Urey is that amino acids will not form in an oxygen atmosphere. Their solution was to assume that the Earth originally had a reducing atmosphere. That means, it had no oxygen, but was composed of methane, ammonia, hydrogen, and water vapor.
They did succeed in producing a small amount Amino Acids. They produced mostly tar, which is poisonous to life. In addition the products had to be removed form circulation so that the spark would not destroy the Amino Acids. If that is not bad enough, with out oxygen there is no ozone layer to block UV rays and UV rays destroy Amino Acids. The final problem is the Earth's "earliest" rocks show evidence of oxygen.
These problems did not stop Miller, he trying again in 1983. They used a neutral atmosphere. It too has no oxygen. It consisted of water vapor, nitrogen, carbon dioxide, and hydrogen. This experiment still had the same problems, but produced fewer results.
The term "simple" cell is actually a misnomer from the late 19th century. Under an optical microscope a cell looks fairly simple. In reality living cells have millions of interdependent proteins. They are incredibly complex systems. Because of this there is no real theory explaining how a living cell could arise from non living mater and life from non life has never been observed. In fact the more is learned about the internal workings of a cell, the more the term "simple cell" becomes a contradiction of terms.
A big problem for a naturalistic origin for life is that with out an organizing mechanism, such a process would violate the Second Law of Thermodynamics. Adding energy will not help with out an organizing mechanism and no organizing mechanism exists for getting life from non life, with one exception: "And God said..."
Actually if some one did produce life in a lab, it would only prove the need for intelligence. So what would the claim that "producing life in a lab proves no need for intelligence" say more about the intelligence of scientists that did it?