Maybe the missionaries’ methods were questionable but their self-sacrifice and zeal were not.
Previously in The Jesuits in North America in the Seventeenth Century.
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The hump-backed sorcerer became a thorn in the side of the Fathers, who more than half believed his own account of his origin. He was, he said, not a man, but an oki, — a spirit, or, as the priests rendered it, a demon, — and had dwelt with other okies under the earth, when the whim seized him to become a man. Therefore he ascended to the upper world, in company with a female spirit. They hid beside a path, and, when they saw a woman passing, they entered her womb. After a time they were born, but not until the male oki had quarreled with and strangled his female companion, who came dead into the world.  The character of the sorcerer seems to have comported reasonably well with this story of his origin. He pretended to have an absolute control over the pestilence, and his prescriptions were scrupulously followed.
[1 Le Mercier, Relation des Hurons, 1637, 72 (Cramoisy). This “petit sorcier” is often mentioned elsewhere.]
He had several conspicuous rivals, besides a host of humbler competitors. One of these magician-doctors, who was nearly blind, made for himself a kennel at the end of his house, where he fasted for seven days. [See Introduction.] On the sixth day the spirits appeared, and, among other revelations, told him that the disease could be frightened away by means of images of straw, like scarecrows, placed on the tops of the houses. Within forty-eight hours after this announcement, the roofs of Onnentisati and the neighboring villages were covered with an army of these effigies. The Indians tried to persuade the Jesuits to put them on the mission-house; but the priests replied, that the cross before their door was a better protector; and, for further security, they set another on their roof, declaring that they would rely on it to save them from infection.  The Indians, on their part, anxious that their scarecrows should do their office well, addressed them in loud harangues and burned offerings of tobacco to them. 
[2 “Qu’en vertu de ce signe nous ne redoutions point les demons, et esperions que Dieu preserueroit nostre petite maison de cette maladie contagieuse.” — Le Mercier, Relation des Hurons, 1637, 150.]
[3 Ibid., 157.]
There was another sorcerer, whose medical practice was so extensive, that, unable to attend to all his patients, he sent substitutes to the surrounding towns, first imparting to them his own mysterious power. One of these deputies came to Ossossané while the priests were there. The principal house was thronged with expectant savages, anxiously waiting his arrival. A chief carried before him a kettle of mystic water, with which the envoy sprinkled the company,  at the same time fanning them with the wing of a wild turkey. Then came a grand medicine-feast, followed by a medicine-dance of women.
[4 The idea seems to have been taken from the holy water of the French. Le Mercier says that a Huron who had been to Quebec once asked him the use of the vase of water at the door of the chapel. The priest told him that it was “to frighten away the devils”. On this, he begged earnestly to have some of it.]
Opinion was divided as to the nature of the pest; but the greater number were agreed that it was a malignant oki, who came from Lake Huron.  As it was of the last moment to conciliate or frighten him, no means to these ends were neglected. Feasts were held for him, at which, to do him honor, each guest gorged himself like a vulture. A mystic fraternity danced with firebrands in their mouths; while other dancers wore masks, and pretended to be hump-backed. Tobacco was burned to the Demon of the Pest, no less than to the scarecrows which were to frighten him. A chief climbed to the roof of a house, and shouted to the invisible monster, “If you want flesh, go to our enemies, go to the Iroquois!” — while, to add terror to persuasion, the crowd in the dwelling below yelled with all the force of their lungs, and beat furiously with sticks on the walls of bark.
[5 Many believed that the country was bewitched by wicked sorcerers, one of whom, it was said, had been seen at night roaming around the villages, vomiting fire. (Le Mercier, Relation des Hurons, 1637, 134.) This superstition of sorcerers vomiting fire was common among the Iroquois of New York. — Others held that a sister of Étienne Brulé caused the evil, in revenge for the death of her brother, murdered some years before. She was said to have been seen flying over the country, breathing forth pestilence.]
Besides these public efforts to stay the pestilence, the sufferers, each for himself, had their own methods of cure, dictated by dreams or prescribed by established usage. Thus two of the priests, entering a house, saw a sick man crouched in a corner, while near him sat three friends. Before each of these was placed a huge portion of food, — enough, the witness declares, for four, — and though all were gorged to suffocation, with starting eyeballs and distended veins, they still held staunchly to their task, resolved at all costs to devour the whole, in order to cure the patient, who meanwhile ceased not in feeble tones, to praise their exertions, and implore them to persevere.
[“En fin il leur fallut rendre gorge, ce qu’ils firent ŕ diuerses reprises, ne laissants pas pour cela de continuer ŕ vuider leur plat.” — Le Mercier, Relation des Hurons, 1637, 142. — This beastly superstition exists in some tribes at the present day. A kindred superstition once fell under the writer’s notice, in the case of a wounded Indian, who begged of every one he met to drink a large bowl of water, in order that he, the Indian, might be cured.]
Turning from these eccentricities of the “noble savage”  to the zealots who were toiling, according to their light, to snatch him from the clutch of Satan, we see the irrepressible Jesuits roaming from town to town in restless quest of subjects for baptism. In the case of adults, they thought some little preparation essential; but their efforts to this end, even with the aid of St. Joseph, whom they constantly invoked,  were not always successful; and, cheaply as they offered salvation, they sometimes railed to find a purchaser. With infants, however, a simple drop of water sufficed for the transfer from a prospective Hell to an assured Paradise. The Indians, who at first had sought baptism as a cure, now began to regard it as a cause of death; and when the priest entered a lodge where a sick child lay in extremity, the scowling parents watched him with jealous distrust, lest unawares the deadly drop should be applied. The Jesuits were equal to the emergency. Father Le Mercier will best tell his own story.
[6 In the midst of these absurdities we find recorded one of the best traits of the Indian character. At Ihonatiria, a house occupied by a family of orphan children was burned to the ground, leaving the inmates destitute. The villagers united to aid them. Each contributed something, and they were soon better provided for than before.]
[7 “C’est nostre refuge ordinaire en semblables necessitez, et d’ordinaire auec tels succez, que nous auons sujet d’en benir Dieu ŕ iamais, qui nous fait cognoistre en cette barbarie le credit de ce S. Patriarche aupres de son infinie misericorde.” — Le Mercier, Relation des Hurons, 1637, 153. — In the case of a woman at Onnentisati, “Dieu nous inspira de luy vouër quelques Messes en l’honneur de S. Joseph.” The effect was prompt. In half an hour the woman was ready for baptism. On the same page we have another subject secured to Heaven, “sans doute par les merites du glorieux Patriarche S. Joseph.”]
“On the third of May, Father Pierre Pijart baptized at Anonatea a little child two months old, in manifest danger of death, without being seen by the parents, who would not give their consent. This is the device which he used. Our sugar does wonders for us. He pretended to make the child drink a little sugared water, and at the same time dipped a finger in it. As the father of the infant began to suspect something, and called out to him not to baptize it, he gave the spoon to a woman who was near, and said to her, ‘Give it to him yourself.’ She approached and found the child asleep; and at the same time Father Pijart, under pretence of seeing if he was really asleep touched his face with his wet finger, and baptized him. At the end of forty-eight hours he went to Heaven.
“Some days before, the missionary had used the same device (industrie) for baptizing a little boy six or seven years old. His father, who was very sick, had several times refused to receive baptism; and when asked if he would not be glad to have his son baptized, he had answered, No. ‘At least,’ said Father Pijart, ‘you will not object to my giving him a little sugar.’ ‘No; but you must not baptize him.’ The missionary gave it to him once; then again; and at the third spoonful, before he had put the sugar into the water, he let a drop of it fall on the child, at the same time pronouncing the sacramental words. A little girl, who was looking at him, cried out, ‘Father, he is baptizing him!’ The child’s father was much disturbed; but the missionary said to him, ‘Did you not see that I was giving him sugar?’ The child died soon after; but God showed His grace to the father, who is now in perfect health.”
[Le Mercier, Relation des Hurons, 1637, 165. Various other cases of the kind are mentioned in the Relations.]
That equivocal morality, lashed by the withering satire of Pascal, — a morality built on the doctrine that all means are permissible for saving souls from perdition, and that sin itself is no sin when its object is the “greater glory of God,” — found far less scope in the rude wilderness of the Hurons than among the interests, ambitions, and passions of civilized life. Nor were these men, chosen from the purest of their Order, personally well fitted to illustrate the capabilities of this elastic system. Yet now and then, by the light of their own writings, we may observe that the teachings of the school of Loyola had not been wholly without effect in the formation of their ethics.
But when we see them, in the gloomy February of 1637, and the gloomier months that followed, toiling on foot from one infected town to another, wading through the sodden snow, under the bare and dripping forests, drenched with incessant rains, till they descried at length through the storm the clustered dwellings of some barbarous hamlet, — when we see them entering, one after another, these wretched abodes of misery and darkness, and all for one sole end, the baptism of the sick and dying, we may smile at the futility of the object, but we must needs admire the self- sacrificing zeal with which it was pursued.
– The Jesuits in North America in the Seventeenth Century, Chapter 8 by Francis Parkman
The below is from Francis Parkman’s Introduction.
If, at times, it may seem that range has been allowed to fancy, it is so in appearance only; since the minutest details of narrative or description rest on authentic documents or on personal observation.
Faithfulness to the truth of history involves far more than a research, however patient and scrupulous, into special facts. Such facts may be detailed with the most minute exactness, and yet the narrative, taken as a whole, may be unmeaning or untrue. The narrator must seek to imbue himself with the life and spirit of the time. He must study events in their bearings near and remote; in the character, habits, and manners of those who took part in them, he must himself be, as it were, a sharer or a spectator of the action he describes.
With respect to that special research which, if inadequate, is still in the most emphatic sense indispensable, it has been the writer’s aim to exhaust the existing material of every subject treated. While it would be folly to claim success in such an attempt, he has reason to hope that, so far at least as relates to the present volume, nothing of much importance has escaped him. With respect to the general preparation just alluded to, he has long been too fond of his theme to neglect any means within his reach of making his conception of it distinct and true.