Amid the prevailing corruption, Methuselah, Noah, and many others labored to keep alive the knowledge of the true God and to stay the tide of moral evil. A hundred and twenty years before the Flood, the Lord by a holy angel declared to Noah His purpose, and directed him to build an ark. While building the ark he was to preach that God would bring a flood of water upon the earth to destroy the wicked. Those who would believe the message, and would prepare for that event by repentance and reformation, should find pardon and be saved. Enoch had repeated to his children what God had shown him in regard to the Flood, and Methuselah and his sons, who lived to hear the preaching of Noah, assisted in building the ark.

Midt i den almindelige fordærvelse arbejdede Metusalem, Noa og mange andre på at holde kendskabet til den sande Gud i live og standse umoralitetens onde flodbølge. Et hundrede og tyve år før syndfloden fortalte Herren ved en hellig engel Noa om sit forsæt og bød ham bygge en ark. Medens Noa byggede arken, skulle han forkynde, at Gud ville bringe en vandflod over jorden for at udslette de ugudelige. De, der ville tro på budskabet og forberede sig til denne begivenhed ved anger og omvendelse, ville få tilgivelse og blive frelst. Enok havde gentaget for sine børn, hvad Gud havde vist ham med hensyn til syndfloden, og Metusalem og hans sønner, der levede længe nok til at høre Noa prædike, hjalp til med at bygge arken.