noun
millenarianism; millennialism; chiliasm
A theological term referring to the belief in a future thousand-year reign of Christ or a golden age. Used primarily in Christian eschatology.
千年説はキリスト教の終末論の一部である。
Millenarianism is a part of Christian eschatology.
彼は千年説を支持する神学者だ。
He is a theologian who supports millennialism.
千年王国 refers to the millennial kingdom itself, whereas 千年説 is the belief or doctrine about it.
Compound of 千年 (sen'nen, 'thousand years') and 説 (setsu, 'theory' or 'doctrine'). The term is a direct translation of the Western theological concept.