I'm, glad you asked. Man's motion can be directed. God the Father has established the goal, Jesus Christ has laid out the path. If we walk w/ Christ our oscillations become eccentric about positive poles; life, good, being, etc.
This is necessarily a conscious, deliberate decision. And it requires effort on our part. The more the effort the closer we move towards becoming eternal. What greater purpose can there be?
Obviously not everyone sees it this way. Many have chosen to make no decision or have consciously disavowed the eternal. What can they be thinking?
Purpose for what? What's the objective. A purpose implies an objective. What does one want or need to be eternal for?
Hank
-Sam Clemens