The only way to receive the Life of God is by belief/faith in Jesus, no belief in Jesus no Eternal Life for a person.
How does accountability factor into a person who has never heard about Jesus. Would there be something God has for these people, like God does for children, youth who have not reached the age of accountability.
The Rapture and the Age of Accountability – Grace Evangelical Society
Are you confident to say that no believers died in the flood, that the only people who died in the flood were unbelievers. Because there are examples in The Bible of God taking the physical lives of disobedient believers.
Not sure your take on the flood, but there was more to the flood than just sinful man. At the time of the flood was also an attempt by satan to keep The promised Messiah from coming into the world. By corrupting the seed of women, by which God promised to bring the Messiah to earth. The birthing of the nephilim was this attempt by satan.