People tend to complicate things, but the concept of inteligetn design (as proposed by Behe, Demski and many others) is very simple and easy to understand.
The theory of ID is based on 2 premises
1 Intelligent design is detectable: there are objective ways to detect design, this is uncontroversial; for example forensic scientists, archeologists, fire experts, detectives, cryptographers, and many other professionals detect design all the time. For example If we go to another planet and find something that looks like pyramids there would be an objective way to determine if they where design or not. And one could (in principle) conclude that these pyramids where intelligently design even if nobody knows who the designer, or where did it come from, or “who created the designer” the answer to those question could simply be “I don’t know”
2 if we apply those objective methods to living things, we would infer design: If we look at living things at apply the same methods that we already know that are reliable, to detect design, we would infer that life was designed by an intelligent designer (even if we might not know who the designer is, or were did he come from)
The objective method that Dembski and others propose is “specified complexity” something is specified and complex if:
1 it has many parts (or units)…. For example a book has many letters
2 they are organized in a pattern…..for example the letters are organized in such a way in which they produce meaningful words and sentences
3 the pattern is independent from the forces of nature: …. For example there is no a law (or principle) in nature that forces “ink” and “paper” to produce meaningful letters words and sentences.
Something requires all (1,2 and 3) in order to call it “specified complexity”
The argument is that life is specified and complex
even the simplest life forms would require many amino acids (1) organized in a very specific order and pattern (2) and nothing in nature forces the amino acids to organize themselves in such a way that they would produce functional self replicating “things”
*For simplicity lets define life as: something organic that can reproduce.
In my experience those who deny ID don’t really present an argument, and usually they don’t spot their point of disagreement, they simply troll and call ID “creationism with another name” instead of providing an actual argument.