To an earlier generation, the word "authenticity" meant that something was verifiable and proven. The dictionary says, "The quality of being authentic, trustworthy, or genuine. Undisputed credibility." Authencity meant that you could prove it beyond the shadow of a doubt. For instance, a famous painting was "authentic" because who actually painted it could be proven. A document could be proven authentic after a painstaking historical investigation and evaluation. It took a rational process to be authentic.
But today, the definition has more to do with a "feeling."
Today, authenticity means that "it feels right." So when a person encounters a religious faith, it's not a matter of investigating the evidence and coming to a rational conclusion – it's about feeling. Does it feel right to me? How do I feel while experiencing it?
It's critical to understand that change in the definition if we're going to be successful in understanding people we talk to and meet. Yesterday, Christianity was authentic to C.S. Lewis because he investigated world religions and evaluated the claims of Christ in a rational, detailed manner. As a result, he decided that Christianity stood up to rigorous questioning.
But today, Wicca or Witchcraft or any number of other trendy religions seem "authentic" to people because they feel right. Sadly, it's not about rational evaluation anymore, it's about feeling. And by moving the needle on the definition of "authentic," another tool for the presentation of a very real experience has been cheapened.
Today, if a person says something is "authentic," it's usually not about being honest or real, it's more that it "feels right" – regardless of the truth of the situation.