From The American Scientist:
As the frontiers of knowledge have advanced, scientists have resolved one creation question after another. We now have a pretty good understanding of the origin of the Sun and the Earth, and cosmologists can take us to within a fraction of a second of the beginning of the universe itself. We know how life, once it began, was able to proliferate and diversify until it filled (and in many cases created) every niche on the planet. Yet one of the most obvious big questions—how did life arise from inorganic matter?—remains a great unknown.
Our progress on this question has been impeded by a formidable cognitive barrier. Because we perceive a deep gap when we think about the difference between inorganic matter and life, we feel that nature must have made a big leap to cross that gap. This point of view has led to searches for ways large and complex molecules could have formed early in Earth’s history, a daunting task. The essential problem is that in modern living systems, chemical reactions in cells are mediated by protein catalysts called enzymes. The information encoded in the nucleic acids DNA and RNA is required to make the proteins; yet the proteins are required to make the nucleic acids. Furthermore, both proteins and nucleic acids are large molecules consisting of strings of small component molecules whose synthesis is supervised by proteins and nucleic acids. We have two chickens, two eggs, and no answer to the old problem of which came first.