Allah created Hazrath Adam (A.S). When he was bored, Allah gave him a companion, Bibi Huwwa(A.S.) then when they were misguided by Shaiytan, Allah send them on earth. After they cried and begged in their dua's for Allah's forgiveness, Allah forgave them and asked them to continue to live on earth and worship Allah until Allah decides to brings them back to their home in the heaven and to see if they continue to be good or not. Since then, generations have passed, every human gets the same test. They all have 2 choices: good and bad. If they choose bad choices and bad things, they will go to hell and be punished and if they choose good choices and good things, then they will go to heaven and the higher their good, the higher they will be in the Jannah level.
The above, tells us that the only purpose for humans to be on earth is to worship Allah every single day and for or every task, we have no choice but to put Allah first. Or thoughts and actions have to be according to Allah's will. If we ever notice that we are unhappy then most likely it is because we are not following Allah's rules.
To ensure we all go to Jannah, we must be good at all times. We must follow the Sunnah and Hadiths and do our best to become like our beloved Prophet Muhammed (PBUH) so that we please Allah. In order to go to Jannah, we must follow 5-Pillars of Islam and 3 Keys to become Supper Special Muslims, they are: (a) Always remain in Ghusl so we can worship Allah whenever and wherever and so that Angels are always closer to us, (b) Always, remain in Wudu so we can perform our namaz and connect with Allah whenever there's a prescribed time and wherever needed so that Angels are always closer to us, (c) Always, be ready to perform our namaz at an exact prescribed time and wherever we are so that Angels can be closer to us. The only way we can become closer to Allah is by sincerely performing the 5-Pillars of Islam and following the 3-Keys with full understanding and the meaning, consistently and systematically.