The question is obviously a very important one, and rather troublesome. For example, in scripture, we have this (KJV):
So according to Matthew, Jesus was very famous, and hundreds of people (indeed, likely thousands) traveled hundreds of miles to see him.
Jesus himself, of course, wasn't just sitting around, either -- he walked all over the place. Here's a map of all the places scriptures says that he visited:
Jesus Travels - sites Maps
Meaning that in addition to all the thousands who traveled to see him, he himself traveled and likely saw thousands more who did not travel themselves. That's thousands of people witnessing thousands of miracles.
The troublesome aspect of this is that the writers and historians of the period make almost no mention of him, and even the few texts where he is mentioned tend to be problematic for various reasons (the Josephus passage, for example, is generally agreed to have been at least partially forged). There are quite a few such people who would have been expected to have written at some length about a man this extraordinary, but never said anything about him at all -- sample list given below.
This is rather worrisome. If the events described in the gospels are, indeed, historically accurate, there should be an overwhelming amount of contemporary supporting material from a wide variety of sources. Instead, we have almost nothing. This makes very little sense if the gospels are historically accurate. However, it makes perfect sense if the gospels are fictional.
-----------------
Historians/writers of the time who made no mention of Jesus:
Apollonius, Persius, Appian, Petronius, Arrian, Phaedrus, Aulus Gellius, Philo-Judaeus, Columella, Phlegon, Damis, Pliny the Elder, Dio Chrysostom, Pliny the Younger, Dion Pruseus, Plutarch, Epictetus, Pompon Mela, Favorinus, Ptolemy, Florus Lucius, Quintilian, Hermogones, Quintius Curtius, Pausanias, Seneca, Justus of Tiberius, Silius Italicus, Juvenal, Statius, Lucanus, Suetonius, Lucian, Tacitus, Lysias, Theon of Smyran, Martial, Valerius Flaccus, Paterculus, and Valerius Maximus.