The Law of Reincarnation and Karma
Until you have resolved your Karma and fulfilled your Dharma, which are the deeds you must do, you will continue to reincarnate into sequential lifetime upon the earth.
Neither God nor the Lords of Karma bestow suffering upon you during these lives, you and you alone decide what you most need to learn and in your earthly sojourns, and for each life experience you seek out other souls, often with shared histories, and always with Karmic configurations matching your needs.
Whenever you act with intention you create Karma. Actions are considered to be thoughts, emotions, words and deeds, and the motive, desire and intent behind each. Disharmonious acts must be balanced in the future in this life or in a future lifetime, to have Soul growth.