The reactions to Sabbatai Sevi in the Jewish world were as varied as can be (up to this very day); he had zealous followers who continued to worship him and adopted his rituals even after his infamous conversion to Islam, and he had bitter and obsessive enemies (some of whom studied him so meticulously that their writings remain important source about Sevi).
Already as a young man who declared himself the Messiah and dared pronounce God’s forbidden name, Sevi provoked the rabbis of Izmir (his birthplace), who expelled him more than once. Between 1651 and 1654, he was excommunicated and forced to leave Izmir. He wandered through Greece, arrived in Istanbul, and around 1659 returned to Izmir only to be forced to leave it in 1662. This time he headed for Jerusalem, an always popular destination for visionaries and anyone with messianic aspirations.
In Jerusalem, he gathered a few followers, and after two years he was sent by the community to Egypt to collect donations. (Some say this was an indication of his high status in Jerusalem, others claim it was an elegant way for the Jerusalem rabbis to get rid of him). In any case, he continued to gather followers, enemies, and fame. He established close contacts with some of the Jewish leaders and in particular with Raphael Joseph Chelbi, one of the richest leaders of the Cairo Jewish community. These connections helped him later in spreading the Sabbatean movement in the Jewish world.
After a few months in Egypt, on his journey back to Jerusalem, Sevi passed through Gaza, and met with a young man, Abraham ben Nathan, known as Nathan of Gaza. Nathan was a prodigious student who had started studying the Kabbalah already at the age of 20, had a strong will for power and a rare charisma with remarkable interpersonal skills. On meeting Sevi, Nathan fell on his knees and vouched complete loyalty to the now officially declared Messiah.
This encounter in 1665 had historical consequences. Nathan became the movement’s prophet and major ideologue, and as a most efficient advocate he had a crucial role in promoting and spreading the word about this Messiah.