In his work for the salvation of souls John met most bitter insults from wicked men who tried in every way to destroy the newly gathered family. But the man of God, bearing all things cheerfully and serenely, defended pertinaciously the fruit of his apostolic labours by securing from the Supreme Pontiff, Gregory XIII, papal approbation of his Congregation. Many bishops about to undertake difficult enterprises sought his advice and aid. Even the Holy Father delegated to him the solution of intricate litigation and the reform of religious societies. He stood in support of Saint Joseph Calasanctius when his society was on the verge of collapse. Scarcely less arduous were the hours John devoted to the affairs of the Hospital of the Holy Spirit in the English section of Rome, and to those of the convent of Saint Frances of Rome.
Greatly saddened that so many peoples in far distant places were without the light of the Gospel, John burned with a desire to journey to those countries to spread the light of the true Faith. But when Saint Philip Neri, who called John a true reformer, shewed him that he and his Congregation were destined to educate the Italian people, John acquiesced to the will of God. He did not, however, refrain so completely that he did not try to do some work for the infidels. He is therefore, very rightly credited along with the pioneer Vives with being the founder of the movement among the bishops to send well-qualified young men to distant, alien lands to propagate the faith. Wherefore he is very properly regarded as the author of that most illustrious institute which augmenteth the work of the Sovereign Pontiffs and serveth to spread the Catholic faith throughout the world. John wrote many works on theology and morality, well adapted to the men of that day. Finally, in sackcloth and ashes, lacking nothing in his sacred ministry, he passed to the Lord in Rome on the 9th day of October, 1609, at the age of sixty-six. He was so famous for sanctity and miracles that Pius IX, the Supreme Pontiff, named him on the calendar of the Blessed. In 1938 on the solemn Feast of Easter, Pius XI enrolled him among the Saints.