If you go around promising what you do not yet have, you will lose the will to achieve it.
Thousands of years ago, weren't we capable of building enormous structures like the pyramids? Weren't we capable of worshiping gods, weaving, making fire, finding lovers and wives, sending written messages? Of course we were. But although we've succeeded in replacing slaves with wage slaves, all the advances we've made have been in the field of science. Human beings are still asking the same questions as their ancestors. In short, they haven't evolved at all.