When the prophet Noah was alive, people were very wicked.
“[But] Noah and his sons hearkened unto the Lord, and gave heed, and they were called the sons of God.” (Moses 8:13)
Because Noah and his sons chose the right, they received the Priesthood. Noah was called to preach the gospel. “And it came to pass that Noah called upon the children of men that they should repent; [Noah said] Believe and repent of your sins and be baptized in the name of Jesus Christ, the Son of God, even as our fathers, and ye shall receive the Holy Ghost, that ye may have all things made manifest; and if ye do not this, the floods will come in upon you; nevertheless [the people] hearkened not.” (Moses 8:20, 24)
Noah was sad that the people would not repent, even though he taught the people a flood would destroy them. “And the Lord said: I will destroy man whom I have created, from the face of the earth, both man and beast, and the creeping things, and the fowls of the air.” (Moses 8: 26) The people were totally wicked and would be destroyed.
But Noah and his sons were still righteous. Heavenly Father commanded Noah to build an ark so he and his family and the animals could survive the flood. They would not be destroyed. Noah was blessed for choosing the right. Heavenly Father protected Noah and his family.