Is it permissible for a postgraduate student to use a foreign reference by a Christian that describes God as "the director" in the context of discussing the symbolism of the Quran, knowing that the author did not intend to cause offense?

What we understood is that the author, by likening Allah to a director, means the prevalent understanding of a director in artistic circles. This meaning is unfitting for Allah Almighty, and it is a form of likening Allah to His creation. Therefore, it is more appropriate to quote from the words of Muslim scholars. If you need to quote from the words of this author, then quote what does not contradict the Sharia, or remove the contradicting word, or keep it while pointing out its error.