Darwinists are celebrating this month the 150th anniversary of the publication of their hero's breakthrough book, On the Origin of Species. Christians who respond with ridicule of Darwin get nowhere—but understanding a few terms of the debate can help to start a dialogue.
(1) Let's start with the distinction between types of evolution. Back in 1859 everyone knew that changes could occur within a species; that's how we breed dogs. Darwin's theory was that a process analogous to artificial breeding also occurs in nature; he called that process natural selection, and he postulated that one species could change into another species. (To put it biblically, since God talks about "kinds" of creatures, one kind could become another kind.)
It's important to know the difference between change within kinds (microevolution) and change from one kind to another (macroevolution). Darwinists who argue for macroevolution often give microevolution examples to "prove" changes. The famous "proof" of moths changing colors as pollution darkened trees was actually a fake, but it could have happened—and that would prove nothing about Darwinism.
Bottom line: Critics of Darwin should not be anti-evolution. Microevolution clearly happens; we should always specify macroevolution.
(2) Let's emphasize how complicated DNA is: In the words of Bill Gates, "DNA is like a computer program, but far, far more advanced than any software we've ever created." So how did DNA come into being? In 1953 James Watson and Francis Crick discovered that DNA stores information in the form of a four-character digital code. Strings of precisely sequenced chemicals called nucleotide bases store and transmit the assembly instructions—the information—for building the crucial protein molecules and machines the cell needs to survive.
The chemical constituents in DNA function like letters in a written language or symbols in a computer code. In other words, DNA functions like a software program—and software comes from programmers who intelligently design it. Bottom line: The makeup of the DNA molecule provides strong grounds for inferring that intelligence played a role in the origin of DNA.