Aka_me, the Guardian's directive can be found in Lights of Guidance...
No. 342 Dramatizing Historic Episodes of the Faith
:As to your question concerning the advisability of dramatizing Bahá'í historic episodes; the Guardian would certainly approve, and even encourage that the friends should engage in such literary pursuits which, no doubt, can be of an immense teaching value. What He wishes the believers to avoid is to dramatize the personages of the Báb, Bahá'u'lláh and 'Abdu'l-Bahá, that is to say to treat them as dramatic figures, as characters appearing on the stage. This, as already pointed out, he feels would be quite disrespectful. The mere fact that they appear on the scene constitutes an act of discourtesy which can in no way be reconciled with Their highly exalted station. Their Message, or actual Words, should be preferably reported and conveyed by Their disciples appearing on the stage." (From a letter written on behalf of Shoghi Effendi to an individual believer, 25 July 1936) Compilation: "Lights of Guidance," p. 99
Blessed is he who mingleth with all men in a spirit of utmost kindliness and love. ~Baha'u'llah