i am a christian, and i found this book to be brilliant (with the exception of the section on memes, which i found to be pedantic)... i believe that anyone -- religious or non-religious, young or old -- should read this book... whether you agree with the conclusions Dawkins draws, these are important questions that have bearing on all of humanity, and this is a very well considered, cohesive, and enjoyable treatise on matters of origin and existence... its a bit slow at times, but on the whole i cannot recommend this highly enough...
You have to train and pass a test to drive a car. Why? Because we're living in a society, and without some agreement on a basic set of rules, chaos ensues and people get hurt. It's a communication problem. Similarly, we all could benefit from everyone being on the same page in regard interpersonal communication.
Just as the fact that you or your associates may be reckless drivers does not invalidate the virtue of traffic laws, the prevalence of liars does not negate the benefits of integrity.
This is pretty academic, and unfortunately the narration really drives that home. Nevertheless, this is as good a treatise on truth as one could hope for: any more concise and it would barely scratch the surface; any longer and it becomes mired in endless examples and repetition.
This isn't for everyone, but if you're interested in a philosophical meditation on truth this should be right up your alley.