7 By faith Noah, being divinely warned of things not yet seen, moved with godly fear, prepared an ark for the saving of his household, by which he condemned the world and became heir of the righteousness which is according to faith.
Noah’s faith was demonstrated by his building of the ark (1 Peter 3:20).
God told Noah to build the ark when he had never seen rain. (Genesis 2:5)
fear — not dread, but reverence for God — awe, circumspection
saving (here) — future blessing
condemned the world — Noah’s faith, in contrast to the mocking unbelief, condemned the world. They had the truth before them in Noah’s faith and warning and they rejected it.
became heir = took into possession, became owner — He possessed righteousness according to (consistent with) faith.