The fear of the LORD is a big topic in Scripture, but it isn’t hard to spot in a believer’s life. One of the clear proofs of a fear of the LORD is obedience to God simply because it was God Who spoke. To obey purely by faith is a mark of those who know God.
Noah is a example of this. In Hebrews 11:7 faith in God meets fear of God in the testimony about Noah. It is through faith, that Noah believed God. And it is in fear, that Noah obeyed God.
God didn’t twist Noah’s arm to believe the promise of a world-wide flood. God didn’t send the Noahic weather bureau a scientific analysis of the coming weather phenomenon. God simply told Noah it would happen.
God simply came to Noah with the full set of plans, told him what would happen, and instructed him to build a floating vessel that could easily withstand 30m waves. The author of Hebrews says Noah obeyed because of a reverent fear of God. When God speaks, no matter what He might say, Noah would obey. The Fear of the LORD enabled Noah to obey purely by faith.
Noah knew that human rationale and time to consider were redundant if God speaks. Look at the account of the actual building of the Ark in Genesis 6. Genesis 6:13-21 is God’s first conversation with Noah. It includes the initial warning and all the instructions. Then verse 22 records the building process. About 100 years are included in v. 22! For a man who fears the LORD, the time required to obey perfectly is inconsequential. It is worth only one short verse. Since we know the end of the story, we know God was right, and therefore it is a good thing Noah obeyed.
The Fear of God produces true obedience based purely on faith in God.
If God said it, then it is the right thing to do, so I’ll do it.