The Elves were tricked by Sauron's deviousness and manipulation. Sauron disguised himself as a beautiful, wise, and benevolent being, and he seduced the Elves with promises of power and glory. He convinced them to create the Rings of Power, which he claimed would give them the ability to control and dominate others. The Elves, being naive and trusting, believed Sauron's lies and created the Rings, not realizing the true purpose behind their creation.