This takes a little time but you are sure to be blessed. I was. I remember reading about all the centuries the men of God lived before the flood and thought it fantastic and it challenged my faith a little, not to mention what must've happened to them at the time of the flood. To do this exercise you might want to use some graph paper, ruler and pencil. Start off with Adam and draw a line on the graph paper and mark where in his life he had his sons, and then draw the line out to Adam's death. Then under Adam draw a line from where his son was born out until he had sons and continue the line out to his death. Do this with each father and son until you reach Noah. Then draw a line out for Noah until the time of the flood. You will be amazed. Our God waited to flood the earth until they all passed away with the last one passed just weeks before the Lord's wrath. The Bible fits like a hand to glove. Keep meticulous track of the years on the graph paper if you really want to enjoy this as you track it out for yourself.