{36a} He "once had a good opinion," he says, of the Liturgy as it now stood, but he soon found that it was full of idolatries.
The most important event in the private life of Knox, during his stay at Berwick, was his acquaintance with a devout lady of tormented conscience, Mrs.Bowes, wife of the Governor of Norham Castle on Tweed.

Mrs.Bowes's tendency to the new ideas in religion was not shared by her husband and his family; the results will presently be conspicuous.

In April 1550, Knox preached at Newcastle a sermon on his favourite doctrine that the Mass is "Idolatry," because it is "of man's invention," an opinion not shared by Tunstall, then Bishop of Durham.

Knox used "idolatry" in a constructive sense, as when we talk of "constructive treason." But, in practice, he regarded Catholics as "idolaters," in the same sense as Elijah regarded Hebrew worshippers of alien deities, Chemosh or Moloch, and he later drew the inference that idolaters, as in the Old Testament, must be put to death.

Thus his was logically a persecuting religion.
Knox was made a King's chaplain and transferred to Newcastle.