Noah is told to bring his house into the ark. As noted before, it is likely that Noah only had the three children, although yet is just possible that he had others who died before the ark sailed, or at least daughters. However, it is almost certain that he did not, since the clear meaning of earlier versus is that those were his only children , Ham, Shem, and Japheth.
God declares
that He has found Noah to be righteous in that generation. This does not mean
that Noah was sinless of course. Remember that all our righteousness is as
filthy rags compared to God's as said in Isaiah 64:6. Rather, just as
with anyone saved by faith - the only way one can be saved, as we see from
effusion 2:8-9 and other places - God looked on him and saw what Christ would
do in the distant future, when He took the sins of all humanity upon
Himself. As stated before, this is just as when Abraham believed God and it was
counted to him for righteousness.
Noah's family
was also brought into the ark. While the Bible does not say they also were
righteous before the Lord, like Job one imagines Noah continually made
sacrifices for his children. He likely told them of what he had heard from his
ancestors, who would have known Adam at an advanced age in fact. And, in the
way he would have shared how Abel's sacrifice was acceptable unto God, because
it was a blood sacrifice just as we see in Leviticus, the life of a creature is in its blood.(Lv. 17:11) Hence he shared with them the fact that one must worship the
creator God and not the creation, and that God would make a way of redemption.
It is not known how clearly Noah understood how God, Jesus Christ, would come
in flesh and be the ultimate sacrifice for our sins - many times the Bible shows that it is His blood which was shed to wash away our sins, with His life being given for us. What we do know is that he trusted
the Lord to make the world new.