Answer
In his second epistle, Peter provides several past examples of God’s judgment, with one of them being the flood described in the book of Genesis. In referencing the flood, Peter mentions Noah as “a preacher of righteousness” (2 Peter 2:5).
The Greek word for preacher is better translated “herald” and refers to an official entrusted with making public proclamations, especially those that are of a transcendent nature. Although we aren’t given the exact content of what Noah preached to those around him, other than the mention of “righteousness,” we can get an idea by examining a couple of Bible passages.
Noah’s world is described as being “corrupt in the sight of God, and the earth was filled with violence. God looked on the earth, and behold, it was corrupt; for all flesh had corrupted their way upon the earth” (Genesis 6:11–12). In His grace, God commissioned Noah to build an ark to preserve himself and his family from the upcoming judgment by water (verse 14).
The long time (possibly 120 years; see Genesis 6:3) it took for Noah and his family to build the ark naturally afforded him the opportunity to share with those around him the reason for the ark’s construction. Apocryphal books such as Jubilees and works like Josephus’ Antiquities contain vague mentions of Noah’s preaching, and one work from ancient history—the Sibylline Oracles—describes Noah’s preaching in this way:
“Single among all men, most just and true,
Was the most faithful Noah, full of care
For noblest works. And to him God himself
From heaven thus spoke: ‘Noah, be of good cheer
In thyself and to all the people preach
Repentance, so that they may all be saved.
But if, with shameless soul, they heed me not
The whole race I will utterly destroy”’ (Book I, lines 155–161).
The only portion of the Bible that alludes to Noah’s subject matter is Hebrews 11:7: “By faith Noah, being warned by God about things not yet seen, in reverence prepared an ark for the salvation of his household, by which he condemned the world, and became an heir of the righteousness which is according to faith” (NASB, emphasis added).
According to 1 Peter 3:19–20, it was Jesus Himself who, in the Spirit, preached “to those who were disobedient long ago when God waited patiently in the days of Noah while the ark was being built.” We take this to mean that, when Noah preached righteousness, he did so by the power of the Spirit of Christ: that is, it was the message of Christ, delivered in the power of Christ, that Noah proclaimed. The ungodly men of Noah’s day had a chance to repent and be saved as Christ preached to them spiritually through Noah. Unfortunately, they rebelled against the truth, refused the ark, and drowned in the flood.
In addition to Noah’s proclamations to the unbelieving world of his day was his “wordless preaching.” In the very construction of the ark, Noah bore witness to righteousness. Every hammer blow, every pounding of a nail was a call to repentance and a declaration that judgment was coming.
Jesus called out the fact that Noah’s contemporaries ignored the message that would have saved them. At the same time, the Lord warned us of making the same mistake: “Just as it was in the days of Noah, so also will it be in the days of the Son of Man. People were eating, drinking, marrying and being given in marriage up to the day Noah entered the ark. Then the flood came and destroyed them all” (Luke 17:26–27).
The point of Peter referencing Noah and others like him in his second epistle is that, if God did not spare the ancient world who rejected Noah’s warnings, how much less can He be expected to spare those who dismiss His calls to repentance today?