The only "thing" we can serve that will make us more ourselves and give us freedom is God. Following His lead will fill our lives with freedom and joy and we will become who we were created to be.
And doesn't that feel great! Have you felt it? You are doing something and you find just joy in it and you know that you know that you know you were created to do that very thing. That feeling, that revelation can only come through Christ (and even if someone hasn't met Him yet if they have stumbled onto this kind of thing and really experience Joy in it it is almost a guarantee that they know it is a gift from above).
Following anything else, living for anything else will slowly, cell by cell take away the person God created someone to be and replace it with a half-person: someone who is alive physically but so lost within -- just wandering around having no clue.
This can even happen to someone who knows Jesus. We can get off-track so terribly that the voice within us who speaks for God will be buried by distractions, worries, ambitions that emphasize the flesh rather than the Spirit. That voice within will be so faint that it will be easily ignored.
YET, if this is you, what can you do? Go back to what you know what you is true and start anew. If you give your whole self to God, He can even take all your stumbling and your wandering, your off-track time and use it all for His kingdom. How can He use it? I have no clue, but He does. He is the ultimate trash into treasure expert.