About five hundred years into the Second Age, Sauron reappeared. "Bereft of his lord...[he] fell into the folly of imitating him." "Very slowly, beginning with fair motives: the reorganizing and rehabilitation of Middle-earth, 'neglected by the gods,' he becomes a reincarnation of Evil, and a thing lusting for Complete Power," eventually rising to become "master and god of Men."
As for Sauron's "fair motives", Tolkien emphasized that at this time he "was not indeed wholly evil, not unless all 'reformers' who want to hurry up with 'reconstruction' and 'reorganization' are wholly evil, even before pride and the lust to exert their will eat them up". "[T]hough the only real good in, or rational motive for, all this ordering and planning and organization was the good of all inhabitants of Arda
(even admitting Sauron's right to be their supreme lord), his 'plans', the idea coming from his own isolated mind, became the sole object of his will,
and an end, the End, in itself. ... [H]is capability of corrupting other minds, and even engaging their service, was a residue from the fact that his original desire for 'order' had really envisaged the good estate (especially physical well-being) of his 'subjects'."
In his early career as an independent power, Sauron did bring material wealth to his subjects: "He made himself a great king in the midst of the earth, and was at first well-seeming and just and his rule was of benefit to all men in their needs of the body; for he made them rich, whoso would serve him. But those who would not were driven into the waste places... [He desired] to be both a king over all kings and as a god to men. And slowly his power moved north and south, and ever westward."