When the theory of Natural Selection emerged, people thought it was a threat to religious beliefs because evolution was not mentioned in the bible. (Pfft! Evolution and Creation! Mutually exclusive? please...)
It allowed for a possibility that life might have appeared without an intelligent creator engineering it.
The first argument against the theory was simple: "You can NOT get order and complexity from random chaos alone."
But what is chaos? Does chaos even exist?
In Thermodynamics, Entropy means that the state of the universe will ultimately fall from a higher level of order to a lower level of order. Chaos will increase. What, then, is our definition of chaos? Anything that does not conform to our definition of order. The further a state is from our definition of order and the harder it is to arrange it into order, the more chaotic it is.
What, then, is order? What is structure? We consider order when something is organized. We consider it a structure designed to carry out a specific function as we see fit. If a water fountain produces water when we press the button and stops when we let go, it is in order. If it takes a longer time to produce water, it is less in order, because it performs its function less well. If it produces too much water, it is further from order. A fountain that never produces water is considered out of order. It cannot perform its function correctly as we intended it to.
How, then, can we define order on an ultimate, universal scale? By comparing the current state of the universe to its ultimate function? What, then, is the function of the universe? How can we know the ultimate function of everything? If we don't know the function of the universe, how can we define order? If we cannot come up with a universal-scale definition of order because the universe has no single function to fulfill, how can we define chaos? If a ball rests on a table, it is doing the job of sitting still well, but not the job of rolling. If a ball rolls, it is performing the function of rolling well, but not sitting still. Ultimately, to define order you must have a clear function of the system you're planning in mind, and an intended function automatically makes the question subjective. If the question is subjective, then there is no universal definition of order.
In Entropy, all things in this universe wish to become constant. We consider this a descent into chaos because it does not allow us or anything else in the universe to perform functions we are used to. We say "our way is order" and "entropy is chaos," but it's just our idea of order. Any state the universe is in, that is its current order, because there is no ultimate form of order.
That said, life did not emerge from "chaos," it simply emerged from a vague sequence of events in the past (the details we will debate elsewhere).