Despite considerable investigation and theorising, the origin of life remains an enigma to those committed to a natural explanation. Some quotations (not from religious people or sources):
“[I]t has to be true that we really don’t have a clue how life originated on Earth by natural means.”
Massimo Pigliucci, “Where Do We Come From? A Humbling Look at the Biology of Life’s Origin,” in Darwin Design and Public Education, eds. John Angus Campbell and Stephen C. Meyer (East Lansing, MI: Michigan State University Press, 2003), p. 196.
“New approaches to investigating the origin of the genetic code are required. The constraints of historical science are such that the origin of life may never be understood.”
J.T. Trevors and D.L. Abel, “Chance and necessity do not explain the origin of life,” Cell Biology International, 28: 729-739 (2004).
“The sudden appearance of a large self-copying molecule such as RNA was exceedingly improbable. … [The probability] is so vanishingly small that its happening even once anywhere in the visible universe would count as a piece of exceptional good luck.”
Robert Shapiro, “A Simpler Origin for Life,” Scientific American, pp. 46-53 (June, 2007).