プロテスタント refers to a major branch of Christianity that originated in the 16th century during the 宗教改革, a movement aimed at reforming the practices and beliefs of the カトリック教会. Key figures, such as マルティン・ルター and ジャン・カルヴァン, challenged the authority of the Pope and emphasized the importance of scripture and personal faith. Protestantism encompasses various denominations, including ルター派, 改革派, and バプテスト, each with unique beliefs and practices. Central to Protestant faith is the belief in salvation through faith alone, the priesthood of all believers, and the authority of the Bible as the sole source of divine revelation.