The Gnostics decided that the three questions that Docetists and Marcionists asked could not be resolved. They realized that mere human logic was inadequate and unnecessary for a personal experience of an unknowable God. However, the claim that faith can be personal and irrational, removes the requirement for priests and scriptures. The Gnostic writings that have survived show that they challenged the very articles of faith that separated believers from non-believers, and Christianity from other religions such as Buddhism and Zoroastrianism, or, for that matter, from insanity and inanity.