Despairing now perhaps more or less of everything, he returned from Rome to England in September 1640, and began to take an active part in the parliamentary troubles in England, and then in 1642 publicly abandoned the Catholic Church for a Puritanical form of Anglicanism. He became a "Preacher of the Word", and as a means to improve the lukewarm reception he had received among Protestants and by the Parliamentarian part, he married. Though for this he was rewarded with the rectorship of Acrise in Kent, he had won for himself general ridicule by a sermon he preached that summer in St Paul's, London, and published in October under the title "The Tyranny of Satan, discovered by the teares of a converted sinner [...] by Thomas Gage, formerly a Romish Priest, for the space of 38 yeares, and now truly reconciled to the Church of England". In December 1642 he testified against the priest Thomas Holland, whom he had known at St. Omer and Valladolid, and obtained a sentence of hanging, drawing and quartering which was effectively carried out. The following year, 1643 it was the turn of the Franciscan Francis Bell, with the same result. On 7 September 1644 the Jesuit Ralph Corby was executed on his evidence.