This is a question many of us ask ourselves. Some of us wonder if we need to withdraw from society and live in a cave or monastery to meditate all day in order to become enlightened. It wouldn't be possible if everyone on Earth chose to do that. And some would argue that the real test is to be an enlightened person while living in society with others, not off somewhere isolated where there are fewer challenges to our peace of mind.
My current thinking about what it means to be enlightened is to understand, to know, that we are each a divine creator. Inside each of us is a spark of the Divine. We create our lives and all of our experiences with our thoughts and emotions. And together, below the level of consciousness, we create the world in which we live. Taking responsibility for what we create and understanding our power as creators is enlightenment. Becoming aware of the Divine in every atom of our being is enlightenment. As Jesus told the people of his time: "You are Gods." (John 10:34).
When I know that within every atom, every cell of my being resides the Divine, then I will be enlightened. When each of us knows this there will be paradise on Earth, a new Golden Age.