The importance of preaching led Eugene to be demanding of his Oblates regarding their preaching methods. In the Rule he insisted that the superior would not allow the missionaries to preach until they had written and studied the sermons that they would preach, which had been examined by two priests appointed by the superior. Often he insisted on each missionary preparing a complete set of sermons and instructions:
Let the youngest amongst you be put to composing a certain number of sermons. I insist that this be stipulated. Father Telmon will be good enough to direct and correct these compositions, this being a duty of charity as much as obedience. He will do well for his own sake to increase his own repertoire. Let him be mindful that there will come a time when the imagination will grow cold and then he will be happy to find in his texts the spirit of his early years…
I shall not rest until I see all of our missionaries who have to announce the Word of God in possession of a complete course of sermons and instructions for retreats and missions. Hold strongly to this point which is essential to the success of your ministry.
Letter to Jean-Baptiste Honorat, 26 March 1842, in O.W. I, n. 10.