The word “perfect” here can be confusing. Noah is not being referred to as flawless, in the way we normally consider perfection. It is not that he is devoid of faults, absent of sin.
“Perfect” is translated in the Greek OT with the word telios. “Telios” might be better translated as “complete”.
Telios shows up as the word “finisher” in Hebrews 12:2 – “[Jesus] is the author and finisher of our faith”.
The idea is that Noah was a complete person. He was just. He was righteous. Noah walked with God; he tried his best, believing God and doing as God commanded. Making his decisions in accordance with God’s way. Noah was “complete” in terms of the kind of life God calls us to.
When Noah built the ark just as God asked him, according to the instructions God gave, Noah illustrates to us what being “complete” looks like. It looks like following God’s ways without any shortcuts. Without any “I think I know better”.
It is comforting we do not have to be perfect, in the modern sense of the word. We are, however, called to complete our ark. To make it seaworthy. To continue working on it until our lives are finished. To seek to do all God asks of us. No more, no less.
Jesus authored our faith. Which means He originated it. He completed our faith, rounding it out. He nailed every sin to the cross and paved our way into heaven. To be a child of God requires simple faith.
To please God requires that we believe He is, and that He is a rewarder of those who diligently seek Him. To have the commitment to “telios”. To complete what God has given us to do.
Our opportunity is to complete our ark through righteous living in the power of Jesus’ resurrection.