"A classic written by one of the Waldensian “barbs” is Jean Leger, Histoire Generale des Eglises Evangeliques des Vallees de Piemont (Leyden, 1669), which was written at the time of the great persecutions and contains firsthand information with drawings. GC 685.2"
"Yea, and all that will live godly in Christ Jesus shall suffer persecution."
The EGW passage describes the persecution faced by the Waldenses, and the Bible verse speaks generally about persecution for those who live godly lives. The connection is thematic, highlighting the shared experience of persecution for religious beliefs.
"Page 77. Edict Against the Waldenses.—A considerable portion of the text of the papal bull issued by Innocent VIII in 1487 against the Waldenses (the original of which is in the library of the University of Cambridge) is given, in an English translation, in John Dowling's History of Romanism (1871 ed.), B. 6, ch. 5, sec. 62. GC 685.5"
"And he had power to give life unto the image of the beast, that the image of the beast should both speak, and cause that as many as would not worship the image of the beast should be killed."
The EGW passage references a papal bull against the Waldenses, while Revelation 13:15 speaks of the beast causing those who don't worship it to be killed. The passages are thematically linked by their discussion of persecution for religious beliefs.