For that generation, the challenge was not too difficult, because as Moses had pointed out to them earlier, they had personally experienced forty years of miraculous survival in the desert wilderness, fed by the daily manna and watered by a spring which accompanied them on their journeys. With such manifestations of Divine wonders, they would not be likely to ascribe any future success to their own strength and cunning. Today, however, many centuries away from the Biblical times, we may think that the world operates purely by natural law. That we can determine our own destiny, in which success or failures are due to how much effort we exert.