What is unforgivable sin, & the test for knowing it's been committed? Part 4/4

Gavin says, "We read in … St. Matthew 12:31 of … unforgivable sin … & in the … 39 Articles … Article 16 … of 'unpardonable sin'." He makes comments about William the Conqueror's General, William de Warrene, 1st Earl of Surrey (d. 1088) who built Lewis Castle, and William de Warren, 5th Earl of Surrey (d. 1240) who started the Stamford St. Brice's Day Bull run tradition. Of the "English tradition of … the Stamford St. Brice's Day Bull Run, ... one element ... is that this issue of sin should remind us to distinguish between man & animals." And in Part 4 we undertake "a case study of Bishop Britius of Tours, to see if he did, or did not, commit unpardonable sin." "Article 16 of the … 39 Articles says, 'Not every deadly sin willingly committed after baptism is sin against the Holy Ghost, & unpardonable. Wherefore the grant of repentance is not to be denied to such as fall into sin after baptism. After we have received the Holy Ghost, we may depart from grace given, & fall into sin, & by the grace of God we may arise again, & amend our lives. And therefore they are to be condemned, which say, they can no more sin as long as they live here, or deny the place of forgiveness to such as truly repent.' And so the 39 Articles here upholds the comforting Biblical teaching that providing he has not committed unpardonable sin … a sinner … can still find 'forgiveness'." And as stated in "Article 11, 'We are accounted righteous before God, only for the merit of our Lord & Saviour Jesus Christ by faith …', & Article 12, '… good works … do spring out necessarily of a true & lively faith: insomuch that by them a lively faith may be as evidently known as a tree discerned by the fruit'."