God gave Noah the plans to build the ark. Noah had to decide to build the boat. God didn't force Noah to build the ark. God had the plan. Others could have and may have made a boat for themselves, but it wasn't the way God designed it. Man can come up with a good plan, but if it's not God's way, that plan won't last. God gave us a way of salvation, but if people try to do it their own way it will not work....EVER.