This story is often referred to the story of the prodigal son. This story, though is about more than one son.
Jesus tells this story about two sons and a father. The two sons take two different paths toward fulfillment.
Tim Keller in his book Prodigal God says that the younger son pursued fulfillment through the path of self-discovery and the older son through the path of moral conformity.
One aimed to find fulfillment through doing what felt good or seemed pleasing to him. The other aimed to find fulfillment through doing "right things."
While both paths miss the mark, it seems Jesus sees the path of the older son as more dangerous.
It is possible to be physically close (in church, in small group, etc.) and spiritually very distant from the Father.