If you’re walking in a forest and you come across a clearing and see an office building, would you assume that building was built by random chance of molecules coming together over billions of years? Of course you wouldn’t!
There are hallways, meeting rooms, walls and a roof. It is a complex structure in the sense that it is highly improbable that this building grew up by random interactions of molecules over billions of years. Not only that but it was built this way by ‘someone’. This designer ‘specified’ how it was to be built. It has a heating & air conditioning system, carpeting, furniture, doors and bathrooms.
Combine these two things and you have ‘specified complexity’. This is the sign of an intelligent designer.

     The Design (teleological) argument says;
1…every design has a designer
2…the universe has a design
3…therefore, the universe has a designer.

     Scientists have discovered the Anthropic Principle that says that the universe is fine tuned to support human life on Earth. One example is the oxygen level in out atmosphere, which is 21%. If it were 25%, fires would break out everywhere spontaneously. If it were 15%, humans would suffocate. There are hundreds of these examples. A list of a few of them can be found at http://godandscience.org/apologetics/designun.html.
Astro-physicist Hugh Ross has found 122 of these examples (there are more). The chance that they would exist by random chance (darwinian evolution) is one chance in the number 1 followed by 38 zeros. This is such a ridiculously small number, it is essentially zero. Cosmologist Ed Harrison says that these examples provide irrefutable evidence of an intelligent designer of our universe.

     Some people propose the Multi-Verse theory to explain these examples but as we point  out in another FAQ, this is speculation for which there is no observational evidence at all. There’s no plausible explanation for the Anthropic Principle other than an intelligent designer. I just don’t have enough faith to believe in darwinian evolution. Our universe is designed for human life because someone designed it that way by a designer (God).

For an excellent short video, go to The Fine Tuning Argument

Book references:
“I don’t have enough faith to be an atheist” by Geisler & Turek, page 95
“The Case for a Creator” by Lee Strobel, the entire book
“What’s so great about Christianity” by Dinesh D’Souza, page 115

Website reference:
http://godandscience.org/apologetics/designun.html