The fate of your next life is clearly stated in Bhagavad Gita.
Your next life is determined by the dominant quality or guna within you at the time of your death. The three qualities Sattva, Raja, and Tamas represents purity, activity, and lethargy, respectively, which bind the soul with the body. If you have Sattva quality dominant, you will get visa to the higher abodes like Sworgalok (~heaven). If you have Raja quality dominant, you will be born as a human being again in a suitable family/environment, to fulfill your remaining desires. If you have Tama quality dominant, you will get visa to Narka (~hell) or be born as some insect or animal. (Gita 14.15)
When you realize that the three qualities are the doer of actions, not you, and find out by experience, the one within you who is faraway, untouched by these three qualities, then you break the cycles of birth and death and become free. (Gita 14.19)