we are the results of our past karmas

According to Buddhist teaching, we are the results of our past karma. However, we can change our fate by doing certain good karmas. For example, if we want to be rich, we should donate very often no matter how small the amount may be. Those who like good health should abstain from killing and taking vegetarian diet is a form of non-killing. In case one wants to be wise, then he should preach the darma to enlighten others.