Speculation is not knowledge.

Does it take a blanket presupposition for a historian to discount some miracle stories as legendary? No, because, as even Bultmann recognized, there is no problem accepting reports even of extraordinary things that we can still verify as occurring today, like faith healings and exorcisms. However you may wish to account for them, you can go to certain meetings and see scenes somewhat resembling those in the gospels. So it is by no means a matter of rejecting all miracle stories on principle. Biblical critics are not like the Committee for Scientific Investigation of Claims of the Paranormal.

In broad outline and in detail, the life of Jesus as portrayed in the gospels corresponds to the worldwide Mythic Hero Archetype in which a divine hero's birth is supernaturally predicted and conceived, the infant hero escapes attempts to kill him, demonstrates his precocious wisdom already as a child, receives a divine commission, defeats demons, wins acclaim, is hailed as king, then betrayed, losing popular favor, executed, often on a hilltop, and is vindicated and taken up to heaven.

Fundamentalism fills you with answers before you even think to ask the questions.

A critic may reject some miracle stories as legendary, and not others, with no inconsistency at all for the simple reason that even if one holds miracles to be possible, one need not hold legends to be impossible! There are other factors, literary and historiographical ones, that might lead a critic to conclude that even though miracles can happen, it does not appear that in this or that case they did.

The born-again gospel promises joy and peace of mind, but it does so by prolonging childhood.

Though [Charles Guignebert] could not accept either the Christ myth theory, which held that no historical Jesus existed, or the Dutch Radical denial that Paul authored any of the epistles, Guignebert took both quite seriously.