Everyone is born with the power of will (to create, procreate or to just exist solely). But we are more capable than each other.
And this is dependent on some factors which are;

Access to basic infrastructural facilities (food, water and power).
Education.
Motivation/inspiration.
Skill acquisition.
Good Health.

The lack or shortage of the above mentioned brings about inequalities amongst us.
People who possess or can afford them tend to be rich and those who cant are poor.