According to Herodotus, the Getae were a godless lot, but they worshipped a certain Zalmoxis. Herodotus also repeats a story current in the local Greek settlements that made this Zalmoxis a pupil of Pythagoras, who worked a con on the ignorant Scythians. He hid in a cave in the ground for three years, and was mourned as dead. Then he reappeared. Apparently this made them think his teaching must be true. Here’s what he says:
The belief of the Getae in respect of immortality is the following. They think that they do not really die, but that when they depart this life they go to Zalmoxis, who is called also Gebeleizis by some among them. To this god every five years they send a messenger, who is chosen by lot out of the whole nation, and charged to bear him their several requests. Their mode of sending him is this. A number of them stand in order, each holding in his hand three darts; others take the man who is to be sent to Zalmoxis, and swinging him by his hands and feet, toss him into the air so that he falls upon the points of the weapons. If he is pierced and dies, they think that the god is propitious to them; but if not, they lay the fault on the messenger, who (they say) is a wicked man: and so they choose another to send away. The messages are given while the man is still alive. This same people, when it lightens and thunders, aim their arrows at the sky, uttering threats against the god; and they do not believe that there is any god but their own.
I am told by the Greeks who dwell on the shores of the Hellespont and the Pontus, that this Zalmoxis was in reality a man, that he lived at Samos, and while there was the slave of Pythagoras son of Mnesarchus. After obtaining his freedom he grew rich, and leaving Samos, returned to his own country.
The Thracians at that time lived in a wretched way, and were a poor ignorant race; Zalmoxis, therefore, who by his commerce with the Greeks, and especially with one who was by no means their most contemptible philosopher, Pythagoras to wit, was acquainted with the Ionic mode of life and with manners more refined than those current among his countrymen, had a chamber built, in which from time to time he received and feasted all the principal Thracians, using the occasion to teach them that neither he, nor they, his boon companions, nor any of their posterity would ever perish, but that they would all go to a place where they would live for ever in the enjoyment of every conceivable good.
While he was acting in this way, and holding this kind of discourse, he was constructing an apartment underground, into which, when it was completed, he withdrew, vanishing suddenly from the eyes of the Thracians, who greatly regretted his loss, and mourned over him as one dead. He meanwhile abode in his secret chamber three full years, after which he came forth from his concealment, and showed himself once more to his countrymen, who were thus brought to believe in the truth of what he had taught them. Such is the account of the Greeks.
I for my part neither put entire faith in this story of Zalmoxis and his underground chamber, nor do I altogether discredit it: but I believe Zalmoxis to have lived long before the time of Pythagoras. Whether there was ever really a man of the name, or whether Zalmoxis is nothing but a native god of the Getae, I now bid him farewell. As for the Getae themselves, the people who observe the practices described above, they were now reduced by the Persians, and accompanied the army of Darius. — Book IV, 93-96.
I discovered yesterday that some people online believe that Zalmoxis is somehow like Jesus, at least to the extent that he has a resurrection in his myth.
When I encounter stuff like that, my first reaction is always to ask to see the data. I compiled all the references I could find about Zalmoxis, which I put here. There isn’t a lot. All the later material reads to me as if it is an embellishment of the account of Herodotus. Finding links between people, and deities, and writing stories about this, was how ancient syncretism worked. By the time of Iamblichus the theurgist, in the mid-4th century, it has to be questionable whether any real information remained on this subject.
So … did Zalmoxis rise from the dead? Herodotus does not say that people thought so. The text would bear that meaning; but it would also bear the meaning that he pretended to be a god or spirit who was appearing to them.
We need to avoid imposing any preconceptions on the text. Which means, of course, that sometimes we cannot say what the text means.