It is often suggested that the NT miracles must be regarded as history because early Christians believed the stories with deep conviction. It must be remembered however that even tho the educated generally dismissed tall tales of healings and powerful displays there were so many such claims in the first century that even normally objective thinkers fell to reporting rumour as fact.
Here are some examples. Read them and see if any sound familiar.
Josephus
Wars of the Jews 6.5.3. Thus were the miserable people persuaded by these deceivers, and such as belied God himself; while they did not attend nor give credit to the signs that were so evident, and did so plainly foretell their future desolation, but, like men infatuated, without either eyes to see or minds to consider, did not regard the denunciations that God made to them. Thus there was a star (20) resembling a sword, which stood over the city, and a comet, that continued a whole year. Thus also before the Jews' rebellion, and before those commotions which preceded the war, when the people were come in great crowds to the feast of unleavened bread, on the eighth day of the month Xanthicus, (21) [Nisan,] and at the ninth hour of the night, so great a light shone round the altar and the holy house, that it appeared to be bright day time; which lasted for half an hour. This light seemed to be a good sign to the unskillful, but was so interpreted by the sacred scribes, as to portend those events that followed immediately upon it. At the same festival also, a heifer, as she was led by the high priest to be sacrificed, brought forth a lamb in the midst of the temple. Moreover, the eastern gate of the inner (22) [court of the] temple, which was of brass, and vastly heavy, and had been with difficulty shut by twenty men, and rested upon a basis armed with iron, and had bolts fastened very deep into the firm floor, which was there made of one entire stone, was seen to be opened of its own accord about the sixth hour of the night. Now those that kept watch in the temple came hereupon running to the captain of the temple, and told him of it; who then came up thither, and not without great difficulty was able to shut the gate again. This also appeared to the vulgar to be a very happy prodigy, as if God did thereby open them the gate of happiness. But the men of learning understood it, that the security of their holy house was dissolved of its own accord, and that the gate was opened for the advantage of their enemies. So these publicly declared that the signal foreshowed the desolation that was coming upon them. Besides these, a few days after that feast, on the one and twentieth day of the month Artemisius, [Jyar,] a certain prodigious and incredible phenomenon appeared: I suppose the account of it would seem to be a fable, were it not related by those that saw it, and were not the events that followed it of so considerable a nature as to deserve such signals; for, before sun-setting, chariots and troops of soldiers in their armor were seen running about among the clouds, and surrounding of cities. Moreover, at that feast which we call Pentecost, as the priests were going by night into the inner [court of the temple,] as their custom was, to perform their sacred ministrations, they said that, in the first place, they felt a quaking, and heard a great noise, and after that they heard a sound as of a great multitude, saying, "Let us remove hence." But, what is still more terrible, there was one Jesus, the son of Ananus, a plebeian and a husbandman, who, four years before the war began, and at a time when the city was in very great peace and prosperity, came to that feast whereon it is our custom for every one to make tabernacles to God in the temple, (23) began on a sudden to cry aloud, "A voice from the east, a voice from the west, a voice from the four winds, a voice against Jerusalem and the holy house, a voice against the bridegrooms and the brides, and a voice against this whole people!" This was his cry, as he went about by day and by night, in all the lanes of the city. However, certain of the most eminent among the populace had great indignation at this dire cry of his, and took up the man, and gave him a great number of severe stripes; yet did not he either say any thing for himself, or any thing peculiar to those that chastised him, but still went on with the same words which he cried before. Hereupon our rulers, supposing, as the case proved to be, that this was a sort of divine fury in the man, brought him to the Roman procurator, where he was whipped till his bones were laid bare; yet he did not make any supplication for himself, nor shed any tears, but turning his voice to the most lamentable tone possible, at every stroke of the whip his answer was, "Woe, woe to Jerusalem!" And when Albinus (for he was then our procurator) asked him, Who he was? and whence he came? and why he uttered such words? he made no manner of reply to what he said, but still did not leave off his melancholy ditty, till Albinus took him to be a madman, and dismissed him. Now, during all the time that passed before the war began, this man did not go near any of the citizens, nor was seen by them while he said so; but he every day uttered these lamentable words, as if it were his premeditated vow, "Woe, woe to Jerusalem!" Nor did he give ill words to any of those that beat him every day, nor good words to those that gave him food; but this was his reply to all men, and indeed no other than a melancholy presage of what was to come. This cry of his was the loudest at the festivals; and he continued this ditty for seven years and five months, without growing hoarse, or being tired therewith, until the very time that he saw his presage in earnest fulfilled in our siege, when it ceased; for as he was going round upon the wall, he cried out with his utmost force, "Woe, woe to the city again, and to the people, and to the holy house!" And just as he added at the last, "Woe, woe to myself also!" there came a stone out of one of the engines, and smote him, and killed him immediately; and as he was uttering the very same presages he gave up the ghost.
Tacitus
Histories 4.81. In the months during which Vespasian was waiting at Alexandria for the periodical return of the summer gales and settled weather at sea, many wonders occurred which seemed to point him out as the object of the favour of heaven and of the partiality of the Gods. One of the common people of Alexandria, well known for his blindness, threw himself at the Emperor's knees, and implored him with groans to heal his infirmity. This he did by the advice of the God Serapis, whom this nation, devoted as it is to many superstitions, worships more than any other divinity. He begged Vespasian that he would deign to moisten his cheeks and eye-balls with his spittle. Another with a diseased hand, at the counsel of the same God, prayed that the limb might feel the print of a Caesar's foot. At first Vespasian ridiculed and repulsed them. They persisted; and he, though on the one hand he feared the scandal of a fruitless attempt, yet, on the other, was induced by the entreaties of the men and by the language of his flatterers to hope for success. At last he ordered that the opinion of physicians should be taken, as to whether such blindness and infirmity were within the reach of human skill. They discussed the matter from different points of view. "In the one case," they said, "the faculty of sight was not wholly destroyed, and might return, if the obstacies were removed; in the other case, the limb, which had fallen into a diseased condition, might be restored, if a healing influence were applied; such, perhaps, might be the pleasure of the Gods, and the Emperor might be chosen to be the minister of the divine will; at any rate, all the glory of a successful remedy would be Caesar's, while the ridicule of failure would fall on the sufferers." And so Vespasian, supposing that all things were possible to his good fortune, and that nothing was any longer past belief, with a joyful countenance, amid the intense expectation of the multitude of bystanders, accomplished what was required. The hand was instantly restored to its use, and the light of day again shone upon the blind. Persons actually present attest both facts, even now when nothing is to be gained by falsehood.
Suetonius
Lives of the Caesars, II.94.1-7
1. . . . It is not out of order to add what came to pass concerning Augustus before he was born, on the very day of his birth, and after, by which one could foretell his great future and continual happiness.
2. Long ago, when a part of the wall of [his home town] Velitrae was struck by a lightning bolt from heaven, it was interpreted that a citizen from Velitrae would rule the world someday. Led by this belief, the Velitrians at once made war on the Roman people, and, after that, they often did so almost to their own extinction. At long last this proved that [the omen] portended the reign of Augustus.
3. Julius Marathus is the authority that, a few months before Augustus was born, a portent occurred in public which warned that nature was about to give birth to a king for the roman people. The frightened Senate resolved that no boy born that year should be trained [for public life]' those who had pregnant wives, became each applied the prophecy to his own family, took care that the Senate's decree was not really obeyed.
4. In the book, by Asclepias of Mendes, I read that when Atia [Augustus' mother] had come in the middle of the night to the solemn rite of Apollo, when her litter had been set in the temple, and while the other women slept [or, went home], she slept. A snake slipped up to her and, after a little while, went out. When she awoke, she purified herself as if coming from her husband's bed. And immediately on her body there appeared a mark colored like a snake, and she could never get rid of it. Therefore, she always avoided the public baths. Augustus was born in the tenth month after this and because of this was considered the son of Apollo.
Atia herself, before she gave birth to him, dreamed that her womb was carried up to the stars and spread out over all the earth and sky. Octavius, the father, dreamed that the radiance of the sun rose from Atia's womb.
5. . . .When Octavius led an army through the remote regions of Thrace, he consulted about his son with barbarian rites in the grove of Father Liber. [Augustus' future reign] was confirmed by the priests, because when the wine was poured on the altar such a great flame shot up that it went beyond the roof of the temple to the sky. Only in the case of Alexander the Great, when he offered a sacrifice on the same altar, did a like portent occur.
6. . . . When Augustus was a baby, as the writing of C. Drusus reports, in the evening his nurse set him in the cradle, which was on the ground floor. The next morning he had disappeared. After a lengthy search, he was found on a very high tower with his face turned toward the sun's radiance.
7. When he first began to talk at his grandfather's country home, he ordered to be silent some frogs who were making a great racket. And from that time, it is said, no frog ever croaked there . . .