The early atmosphere had no oxygen. The gases that were present then combined during lightning strikes to form amino acids. The mixture of amino acids and sea water is called the ‘primordial soup’. The amino acids combined to form proteins, which grouped to form living cells. Cells came together to form micro-organisms. All life came from these first microbes.
The Facts Are .....
The classic experiment carried out by Stanley Miller (& Urey) in 1953 where amino acids were synthesized in the laboratory, is now largely regarded as a dead end. Similarly regarded today is Sydney Fox's production of proteinoids, which were circular blobs that he claimed were protocells. 
"The problem of the origin of life has turned out to be much more difficult than I, and most other people, envisaged." A statement by Stanley Miller (the researcher who rose to world fame in 1953 by creating amino acids in the laboratory) 
A study of rocks of all ages shows overwhelmingly that they were formed under the influences of an atmosphere containing oxygen. As this is the case, the early atmosphere definitely contained oxygen. Therefore, the 'primordial soup' could never have happened. Nobel Prize winner Francis Crick acknowledges this fact. 
"It is suggested that from the time of the earliest dated rocks ..... Earth had an oxygenic atmosphere." Written by Harry Clemmey & Nick Badham in their article "Oxygen in the Precambrian Atmosphere: An Evaluation of the Geological Evidence" 
The 'first cells' could not have survived the high solar ultraviolet radiation levels that would have existed in an oxygen-less environment, as there would have been no ozone to absorb the rays and shield them.
"..... in the atmosphere and in the various water basins of the primitive earth, many destructive interactions would have so vastly diminished, if not altogether consumed, essential precursor chemicals, that chemical evolution rates would have been negligible. The soup would have been too dilute for direct polymerization to occur. Even local ponds for concentrating soup ingredients would have met with the same problem." 
The chemical reaction in biogenesis that is supposed to have joined amino acids into peptides is a reversible reaction. This means that the reaction goes backwards and turns the peptides immediately back into amino acids. In the non-living environment both the forward and reverse reaction would have been going on at the same time. If the conditions were such that the reverse reaction went faster, then the effect over a long period of time would be that no amino acids would have formed. 
Although amino acids may form in watery conditions, the next step where amino acids spontaneously joining to form peptides, requires dry conditions. Under dry conditions, the subsequent steps to form cells containing a large percentage of water could not proceed.
"The probability that at ordinary temperatures a macroscopic number of molecules is assembled to give rise to the highly ordered structures and to the co-ordinated functracterizing living organisms is vanishingly small. The idea of spontaneous generation of life in its present form is therefore highly improbable, even on the scale of the billions of years during which prebiotic evolution occurred."
"There is a hitch ..... proteins cannot form without DNA, but neither can DNA form without proteins. To those pondering the origins of life, it is a classic chicken-and-egg problem?" 
"Considering the way the prebiotic soup is referred to in so many discussions of the origin of life as an already established reality, it comes as something of a shock to realize that there is absolutely no positive evidence for its existence." 
"Furthermore, no geological evidence indicates an organic soup, even a small organic pond, ever existed on this planet. It is becoming clear that however life began on earth, the usually conceived notion that life emerged from an oceanic soup of organic chemicals is a most implausible hypothesis.
We may therefore with fairness call this scenario 'the myth of the prebiotic soup'." 
"The notion that not only the biopolymers, but the operating programme of a living cell could be arrived at by chance in a primordial soup here on Earth is evidently nonsense of a high order." Written by Sir Fred Hoyle in his article "The Big Bang in Astronomy" in New Scientist, Vol. 92, No. 1280, November 19, 1981 p:527
"In short there is not a shred of objective evidence to support the hypothesis that life began in an organic soup here on the Earth." 
"However, the macromolecule-to-cell transition is a jump of fantastic dimensions, which lies beyond the range of testable hypothesis. In this area all is conjecture. The available facts do not provide a basis for postulating that cells arose on this planet." 
"It is therefore a matter of faith on the part of the biologist that biogenesis did occur and he can choose whatever method of biogenesis happens to suit him personally; the evidence for what did happen is not available." 
The probability that a self replicating protein (one with at least 400 linked amino acids) forms by chance has been calculated as 1 chance in 10450. The rational probability for this is zero. If as the theory of evolution proposes, these amino acids come together through chance step-by-step processes, then the probability for this protein forming is the sum of the probabilities for the formation of each step. The probability for this is enormously larger than the 10450 probability for it happening in one step. This means that it is even more unlikely to have occurred. 
Without oxygen in the atmosphere there would be no ozone to filter out most of the cosmic rays.
As a result, all of the ammonia and methane would have been destroyed in a few thousand years. 
- Scientific American, February, 1991 p:100-109
- in Scientific American, February 1991, p:100-109
- New Scientist, Vol. 87, July 10, 1980 p:112; Geology, Vol. 10, March 1982 p:141
- in Geology, Vol. 10, March 1982 p:141
- Science News, December 24 & 31, 1988 p:423
- Written by biochemists Charles B. Thaxton, Walter L. Bradley & Roger L. Olsen as a statement that biogenesis (chemical evolution) could not have formed in the way evolutionary theory demands. Written in their book "The Mystery of Life's Origin: Reassessing Current Theories", Philosophical Library: New York, 1984 p:66
- A.E. Wilder-Smith, "The Natural Sciences Know Nothing of Evolution", Master Books: San Diego, 1981 p:9-14
- Science News, Vol. 134, 1988 p:117; Nature, August 18, 1988 p:609-611
- Written by Ilya Prigogine, Gregoire Nicolis & Agnes Babloyants in "Thermodynamics of Evolution", Physics Today, Vol. 25, November 1972 p:23.
- From John Horgan's article "Trends in Evolution: In the Beginning ....", in Scientific American, February 1991, p:100-109
- Written by Michael Denton in his book "Evolution: A Theory in Crisis", Alder & Alder: Bethesda (Maryland),1986 p:261
- Written by biochemists Charles B. Thaxton, Walter L. Bradley & Roger L. Olsen in their book "The Mystery of Life's Origin: Reassessing Current Theories", Philosophical Library: New York, 1984 p:66
- Written by world-famous physicist and astronomer Sir Fred Hoyle in his book "The Intelligent Universe", Michael Joseph: London, 1983 p:23
- Written by David E. Green (Institute for Enzyme Research, University of Wisconsin, USA) & Robert F. Goldberger (National Institutes of Health, Maryland, USA) in their book "Molecular Insights into the Living Process", Academic Press: New York, 1967 p:406
- Written by Professor G.A. Kerkut (Department of Physiology and Biochemistry, University of Southampton) in the book "Implications of Evolution", Pergamon Press: London, 1960 p:150
- Analytical Chemistry, Vol. 33, June, 1961 p:23
- NASA Atmospheric Scientists’ opinion in Origins of Life, Vol 12, 1982