You will also find in the dictionary that one meaning of the word religious is "scrupulously faithful." This is where I believe that atheists are religious. Although most are adamant that they have no beliefs, the opposite is true. Atheists have great faith.
In the face of an incredibly intricate and ordered Nature, they believe that there is no evidence of intelligent design. That takes amazing faith.
They believe the idea of evolution. They believe that there is evidence that proves the theory to be a scientific fact. They also believe the earth is billions of years old, and scoff at anyone who doesn't believe as they do.
Look at Talkorigin's take on the age of the earth:
"The generally accepted age for the Earth and the rest of the solar system is about 4.55 billion years (plus or minus about 1%). This value is derived from several different lines of evidence."
So you can confidently believe that the earth is about 4.55 billion years old, if you have faith in radiometric dating methods.
Let's look briefly at the track record of beliefs about the earth's age. In the late 1700's the earth was believed to be about 75,000 years old.
In 1862, calculations changed that belief to between 20 million and 400 million years. Then it was changed to 56 million years old. In 1897 it went back to 40 million, then later to 80 to 100 million years.
When radiometric dating was invented that changed the belief to between 250 million to 1.3 billion years. In 1927 that was changed again to 1.6 to 3.0 billion years.
However, "modern" dating methods changed the belief once again to around 4.53 to 4.58 billion years. Modern folks tend to forget that all past dating methods were thought around the time they were done, to be "modern."
It time, future "modern" dating methods will no doubt change the date once again, and when that happens, the faithful will believe they have the truth. This is because they have unquestioning faith in what they are told. That's because they are "Faitheists" —the scrupulously faithful followers of the religion of atheism.
By the way; the Federal Bureau of Prisons lists "Atheism" under "Religious Categories." So for those atheists who are brave enough to fess up to their non-beliefs when the law catches up with them, they won't feel alone.
