As you have learned from your reading, Buddhists (and Hindus too) believe in the concept of karma. If the situation we find ourselves in during this life is the result of actions in a previous life, then how should we act now? If we see someone who has problems or for whom life is difficult and unhappy, why should we help that person if the unhappiness or suffering is merely the result of what he or she did in a previous existence? Should we offer no charity or compassion?