He challenged every minister he encountered, even the most learned and famous, such as Moulin, David Blondel, Daillé, or Bochard.
Having secured from Louis XIII letters patent authorizing him to deliver his sermons in public and to conduct conferences with the ministers or any other Protestants wheresoever he pleased, he went to Paris, to Charenton, where he was curé for 10 years (1638–48), because Calvinism had there its chief stronghold.
He preached before large audiences; ministers such as Boule, after having heard him, abjured Calvinism after 30 years in the ministry.
Véron became the most celebrated controversialist in France; the general assembly of the clergy assigned him a pension of 600 livres yearly and accepted the dedication of some of his books of which it defrayed the expenses; the Estates of Languedoc undertook his support while he preached in their province; Pope Gregory XV sent his encouragement.
On the other hand, it is of great importance to set forth the doctrine of the Church in all its purity; thus explained, it is entitled to the respect and the acceptance of heretics; hence it is important to separate authentic points of doctrine from what the heretics confuse with it, for example all the opinions of the schools, historical errors, popular legends, or private practices.