Theists: Should the child pay for the sins of their parents?

when a nation was destroyed it was always for great wickedness. but God demonstrated his love for these nations as well when you consider Jonah was sent to Nineveh and God relented of the judgment because they repented. In these instances where the death of the whole was ordered it is like a guy breaking into your house and you kill him so he does not kill you. These nations that did not get wiped out did repopulate and come against Israel in the future. The kids who had not attained an age of accountability might well be received in heaven. The sins that required death by stoning were rarely carried out and the acceptance of the forbidden behavior ended up being the result of not purging the evil. Look back at the USA form say the 20's through early 50"s and you can see where a moral line is crossed and that moral line is in constant retreat from that point on. A Christian is not under the law so the example of Jesus when they brought up a woman caught in adultery and he said he who is without sin may cast the first stone..that rules me out..then he said I do not condemn you but go and sin no more. God is here to save that which is lost; the unjust are already under condemnation. When Israel committed the same acts that God condemned the other nations for He rightly judged them by the same standard yet in His mercy always left a remnant to grow and inherit the promise.