How old does someone need to be before God begins to judge them? In Numbers 14:29, the people under the age of 20 were not judged because of their youth. However, this does not at all imply that this is the fixed age for all people. God was working in this nation in a specific way, and it should not be used to justify a universal age of accountability. The Bible doesn’t give us an age, because different people mature in different stages. It’s likely that the age of accountability is different for each person, dependent upon mental development and maturity.