The Law of Cause and Effect

The Law of Cause and Effect is also called "The Law of Karma". Kamma is action, in general meaning including all kinds of will and itention, good and also bad, physically and also mentality, by mind, words, and actions. Karma is all wills or itentions including good will or bad will. On Anguttara Nikaya III : 415 , Lord Buddha had ever said that , "Itention to act. That's I call as karma. After willing, then people act by its physically, words, or mind"

Karma is not a teaching that makes people despair, not also teaching about a destiny that has been determined. It is true if everything in the past influence present condition. And the future condition is determined by own our selves (present condition). On Samyuta Nikaya I, Lord Buddha had ever said,
"According to seeds that have ever been spread, so that's fruit that it will get.
Benefaction creator will get advantages. Badness creator will get disadvantages.
Spread the seed and you will get the fruits of them"

So, all kinds of condition in this life have reason. In Buddhism, God doesn't make people suffering. And God also doesn't make people happy. In Buddhism, God is not a personal thing.
Suffering or Happy is determined by its own self. Griefs in the world are not a temptation from God. And awards that have happened are not a gift from God. The cause of griefs and awards is karma. The Law of Karma can explain the conditions in the world satisfy. The Law of Karma can explain why there are rich people, poor people, health poeple, sick people, etc.