Section 50 ... After the departure of the Lamanite Missionaries to Missouri and before the arrival of Joseph Smith in Kirtland, Ohio (February 1831), extreme spiritual abnormalities were manifested among new converts in the Kirtland area. ...
Parley P. Pratt, an eyewitness to these events, recorded the following:.
As I went forth among the different branches, some very strange spiritual operations were manifested, which were disgusting, rather than edifying. Some persons would seem to swoon away, and make unseemly gestures, and be drawn or disfigured in their countenances. Others would fall into ecstacies, and be drawn into contortions, cramps, fits, etc. Others would seem to have visions and revelations, which were not edifving, and which were not congenial to the doctrine and spirit of the gospel. In short, a false and lying spirit seemed to be creeping into the Church.
To determine the nature of the spiritual workings among new converts of the Church, Elder Pratt, among others, went to Joseph Smith and asked him to inquire of the Lord concerning the matter. "After we had joined in prayer in his translating room," said Pratt, Joseph Smith "dictated in our presence" section 50.
Section 50 gave instructions on the procedure of discerning "the spirits which have gone abroad in the earth."
[Cook, Lyndon, Revelations of the Prophet Joseph Smith: A Historical and Biographical Commentary of the Doctrine and Covenants, http://amzn.to/RevelationsofJosephSmith]