Many people have various goals in life that they call “purpose”, but purpose is higher level than goals.
Goals are specific attainable objectives, often time bound.
Purpose or mission is broader and deeper1, it lasts without an end.
Goal is a place that we want to reach, purpose is the direction we want to go.
Goals are what we do, purpose is why we do it.
Leading a successful company, winning an Nobel Price, building a family all are goals in life, but not really the purpose. Goals stem from a purpose. Living for God can be purpose for a religious person, sustainable survival can be a purpose for a rational person.
If you ask rational people what their purpose of life is, those who have an answer at all will often speak of family, of making positive contribution to the world and to other people. Some take the very naturalistic view of spreading of our genes as the ultimate purpose of our existence. But if we go a level higher in abstraction, to identify the underlying purpose of many of their goals, we can find surprising consistency in the many of these rational theories… they ultimately aim towards sustainable survival.