Luke 3:36 shows Jesus line of descent all the way back to Noah and Adam. Then Jesus spoke of the flood of Noah's day Luke 17:26,27 and Matthew 24:37. He is a far better source of truth than man. Then Hebrews Speaks of Noah as one of the men of faith Hebrews 11:7. Jesus saw it all. No one would say he never existed. He also said concerning God's Word "Your Word is truth."