One of the most well-entrenched myths of the last 300 years is that one's religious faith is a private matter. In the modern period, Western culture challenged the church to prove on scientific grounds that the claims of the Bible are true. Attempts were made, but by and large the church retreated to the only safe place it had: the interior of the human individual. Faith was seen as a private matter -- something that happens only between the individual and God. Consequently, no one else can judge the authenticity of one's faith.
In today's postmodern culture, the individual still reigns supreme. In fact, Western individualism is more radical than it has ever been. Each individual is free to choose his or her own brand of faith, and "haters" are rebuffed with postmodernism's trump card: "Don't judge me."