This article is from the Wicca FAQ, by firstname.lastname@example.org (Rain of Teleport) with numerous contributions by others.
Since much of Wicca is more worldview and ceremonial practice than
anything else, there is no Wiccan proscription of such things. Most
traditions have no requirement to denounce any other faith and, indeed,
Wiccans often look askance at "one true wayisms" which claim to have a
monopoly on truth, divine revelation or enlightenment. "Christian
Wiccans" probably face the largest skepticism, however, given the history
and ongoing reality of allegedly "Christian" persecution.
Prejudice (fear of job-loss, child-custody challenges, ridicule,
vandalism and even violence) may still keep many Wiccans "in the broom
closet," with concealment and dual observances a traditional Wiccan
defense against persecution. This may make contact with Wiccans
difficult in some areas. Since Wiccan worship is fairly active by its
nature, non-participating observers are rarely invited to Wiccan rituals.