The point (reason) of having a final judgement is that...
it is very seldom that people die as soon as they accept Jesus, they usually continue living. HOW they lead their life AFTER accepting Jesus as Savior is going to show whether they truly accepted Jesus IN THEIR HEART and REPENTED.
Many people are disappointed that they cannot continue to do whatever they feel like doing and at the same time ensure an afterlife with God, they had hoped that they could be "sly" and have everlasting life while continuing to do whatever they wish and still play head games on others in order work out their schemes (They had hoped to play a scheme on God also). God did not send His Son to make peace on earth (so that everyone could be happy continuing to do whatever they want), He sent His Son to make a clear division between right and wrong because people don't usually make a clear division (people usually try to justify everything as "sneaky" and "naughty" or make "excuses" of some kind), but right is right and wrong is wrong and never the twain shall meet. The change from good to evil is clear and abrupt with no middle ground (no shadow or variation due to change, James 1:17).