Tertullian

Furthermore, with respect to the repentance which occurs in his conduct you interpret it with similar perverseness just as if it were with fickleness and improvidence that he repented, or on the recollection of some wrongdoing; because he actually said, “I repent that I have set up Saul to be king,” very much as if he meant that his repentance savored of an acknowledgment of some evil work or error. Well, this is not always implied. For there occurs even in good works a confession of repentance, as a reproach and condemnation of the man who has proved himself unthankful for a benefit. For instance, in this one case of Saul, the Creator, who had made no mistake in selecting him for the kingdom and endowing him with his Holy Spirit, makes a statement respecting the goodness of his person, how that he had most fitly chosen him as being at that moment the choicest man, so that (as he says) there was not one like him among the children of Israel. Neither was he ignorant how he would afterwards turn out. For no one would bear you out in imputing lack of foresight to that God whom, since you do not deny him to be divine, you allow to be also foreseeing; for this proper attribute of divinity exists in him. However, he did, as I have said, burden the guilt of Saul with the confession of his own repentance; but as there is an absence of all error and wrong in his choice of Saul, it follows that this repentance is to be understood as upbraiding another rather than as self-incriminating.

The devil has power that might be called his own, only over such as no longer belong to God, the heathen whom he considers once for all as a drop in a bucket, as dust on the threshing floor, as spittle in the mouth—and, as such, totally handed over to the devil as a quite useless possession.Otherwise, he may do nothing by his own right, against those who dwell in the house of God, because the cases that are noted in Scripture show us when—that is, for what reasons—he may touch them. The right to tempt a person is granted to the devil, either for the sake of a trial, as in the texts cited above, whether God or the devil initiates the plan, or for the purpose of the reprobation of a sinner, who is handed over to the devil as to an executioner. This was the case with Saul. “The spirit of the Lord departed from Saul, and an evil spirit from the Lord troubled and stifled him.” Again, it may happen in order to humble a person, as Paul tells us that there was given him a thorn, a messenger of Satan, to buffet him, and even this sort of thing is not permitted for the humiliation of holy ones through torment of the flesh, unless it be done so that their power to resist may be perfected in weakness.

When the disciples had been hungry on the sabbath and had plucked some ears [of grain] and rubbed them in their hands, they violated the holy day by so preparing their food. Yet Christ excuses them and even became their accomplice in breaking the sabbath. … For from the Creator’s Scripture and from the purpose of Christ there is derived a vivid precedent from David’s example when he went into the temple on the sabbath and provided food by boldly breaking up the show bread. Even he remembered that this privilege (the dispensation from fasting) was allowed on the sabbath from the very beginning, from when the sabbath itself was instituted. For although the Creator had forbidden that the manna should be gathered for two days, he permitted it on only one occasion—the day before the sabbath—so that the previous day’s provision of food might free them from fasting on the following sabbath. Therefore the Lord had good reason for pursuing the same principle in the “annulling” of the sabbath (since that is the word which people will use). He had good reason, too, for expressing the Creator’s will, when he bestowed the privilege of not fasting on the sabbath. In short, might he have—right then and there—put an end not only to the sabbath but to the Creator himself if he had commanded his disciples to fast on the sabbath, as this would have been contrary to the intention of the Scripture and of the Creator’s will. But is he alien from the Creator because he did not directly defend his disciples but excuses them? Or because he interposes human need, as if deprecating censure? Or because he maintains the honor of the sabbath as a day which is to be free from gloom rather than from work? Or because he puts David and his companions on a level with his own disciples in their fault and their validation? Or because he is pleased to endorse the Creator’s indulgence? Or because he is himself good according to his example—is he therefore alien from the Creator?

Why, even now the followers of Simon [Magus] are so confident of their art that they undertake to bring back the souls of the prophets from hell. And this, I believe, because their power lies in their ability to deceive. This power was actually granted to the witch of Endor, who brought back the soul of Samuel after Saul had consulted God in vain. Apart from that case, God forbid we should believe that any soul, much less a prophet, could be called forth by a demon. We are told that “Satan himself is transformed into an angel of light”15—and more easily into a man of light—and that at the end he will work marvelous signs and show himself as God, so much so that, “if possible, he will deceive even the elect.” He hardly hesitated to declare to Saul that he was the prophet [Samuel] in whom the devil was then dwelling.So, you must not think that the spirit which created the apparition was different from the one who made Saul believe in it; but, the same spirit was in the witch of Endor and in the apostate [Saul], and so it was easy for him to suggest the lie that he had already made Saul believe. Saul’s treasure, indeed, was then where his heart was, where God most certainly was not. Thus, he saw only the devil, through whom he believed he would see Samuel, for he believed in the spirit who showed him the apparition.