All the things in the world consist of origin, foundation, and environment. Through the combination of these three things, a new result is formed.
For example, a plant seed(origin) is planted in the ground(foundation) and results in fruits under its environment(water, sunlight, nutrients, temperature, etc.). For reference, those fruits(result) can become seeds for the next year, which is called the phenomenon of repitition.
The same is true of human beings. A soul(origin) meets parents, is born, leads a life in the environment (family, society, country, era, religion, culture, etc.), and makes a newly changed soul through the life. This new soul can become an origin for the next life by the phenomenon of repitition.