God has given his commandments and has told people what is forbidden and what is permissible. These are the fundamental guidelines that have been set to see if an individual will pass or fail their test in this temporary life.This is more of an argument for Heaven than Hell, besides the first paragraph.
As for the first paragraph, eternity is significantly more different than "long-term".
An individual is not punished for not getting a degree because he failed an exam. You don't go to Hell for not doing good deeds. You go to Hell for committing sins.
If the individual cheated in the exam, then a punishment would occur. He's probably be expelled.
Many of the youth are being led astray by the whispers of satan, but you mustn't relent. He is our most avowed enemy and as he said "Then I shall come upon them from before them and from behind them and from their right hands and from their left hands, and Thou wilt not find most of them beholden (unto Thee)"(7.17).
You can only bring about faith from within yourself, but if you have been far from most of the recommended practices from the sunnah your iman being lowered can cause you to be confused about your faith. I would definitely suggest increasing prayers and reading of the Quran, especially the tafseer and i'A this will alleviate your uncertainty.
May Allah keep us all steadfast in our faith and protect us from the whispers of iblis, ameen.