Who are you? It seems like a simple question yet it's much harder to answer than you would think. Unless you've already gone through the introspective process of discovering who you are - then you might have a solid answer. Even then, the question takes a lifetime to answer as we change and grow through various seasons of our lives.
Now, let's look a that question again. Who are you? Before you start listing off titles, consider this - those don't matter. Titles don't convey a sense of identity. They are descriptors of a job. Here are a few of the titles I've held at some point, some current, some past: husband, father, dental tech, pastor, treasurer, company commander (not actual military, I was in ROTC in high school), manager, director of mobile application engineering.
That list of titles says nothing about my identity though. They merely convey a job I do or have done at some point. There's no attachment to identity though. Being a husband and father doesn't actually say anything about me. It only takes a piece of paper to be a husband. It only takes sex to be a father. Being a dental tech means I had a job. In most cases, it only takes a piece of paper to be a pastor. And so on. See what I mean? Titles are just descriptions of a position, job, or task that you perform. They have little to do with your identity.
I've never been a fan of titles because it's too easy for people to get wrapped up in them. Take for instance the last one on my list - director of mobile application engineering. That's my current job title. I don't usually tell people that. Why? Because it doesn't matter. Let me explain that title a bit. I'm a co-manager of a brand within our company. I deal with the development side of things while the other co-manager deals with the design side. I'm the head of the Android and iOS development team. Sounds impressive, doesn't it? That's exactly why I don't spout my title off - it draws too much attention to me and that goes against my personality. So when people ask what I do, I say I'm a web and app developer. It's much simpler, people understand what it means right away, and I don't sound self-important.
See what I did with that example? My identity is strewn in there. I'm an introvert. I don't like being the center of attention. Those describe part of who I am, not what I do. That's not to say what you do isn't important, because it is. Action is tied to your purpose, not your identity. Your identity can help or hinder your purpose, depending on how well you understand yourself, your strengths, and your weaknesses.
Your identity is who God made you to be. What makes you tick? What brings you joy? What brings you pain? What brings out compassion in you? What causes you to cry during a movie/song/game? Are you outgoing or reserved? These kinds of questions are tied to your identity. They answer who you are, not what you do.
If you really want to get into the crux of identity and titles, consider this. In Galatians 3:28, Paul writes, "There is neither Jew nor Greek, there is neither slave nor free, there is no male or female, for you are all one in Christ Jesus." Leading up to this, Paul was talking about how the law showed us that we were prisoners to sin but Jesus set us free and made us children of God. Paul stripped away the titles (religion, status, and even gender) to show us our identity in Christ. It's not by what we do that we have our identity. It's by who we are and whose we are that gives us our identity. In heaven, there will only be one title given to all people - "sinner saved by grace."