Can Christians Use a (Non-Christian) Mantra?

A reader, who identifies as a contemplative/mystical Christian, posted this question to me on Facebook:

Carl….when I meditate/contemplative prayer…can I use a mantra such as-OM or Hare Krishna or something similar?

It’s a great question, and the short answer is, it depends.

Some Christians are allergic to the very idea of a mantra. They see it as the impor…