By Will Green
One concern that a lot of people who aren't Christian have about the Christian concept of heaven is that you have to be a certain kind of person to go to heaven. That is, you have to fit a certain set of personality traits; you have to conform to whatever personality God says you need to have. And these traits won't necessarily be ones that you see as really being 'you'.
One response to this is that you can divide personality into two areas: personality and character, and that improvements in character never betray who we really are, and God only changes character.
Personality is like whether you are introverted or extroverted, whether you like reading, sports, horror movies, video games, etc. Character is whether you treat other people in the way you would like to be treated, i.e., your tendency to do the right thing.
An example of why this distinction is important comes from this thought experiment: if you are an introvert, you would probably feel like becoming an extrovert would 'betray' who you really are as a person, and if God imposed extroversion on you, it would seem a bit like mental slavery, perhaps. But think about this: does anyone feel that way when it comes to changes in character?
I would contend that everyone always accepts improvements in character as being consistent with who they really are. For example, suppose you had someone who was really rude to staff at restaurants and other places, and then someone is rude to them one day and they feel bad about it, so they decide not to be rude to staff any more. Nowhere in this process, it seems, would they stop and say, "Hang on, being more empathetic and treating people the way I'd like to be treated is not consistent with my true self!" It seems that if someone has realised that they ought to relate to people differently, there would be no sense of betrayal of one's true self.
These examples illustrate how the problem is resolved when you say that God changes us in character, not in personality. So when God changes us it's more like someone suddenly realising they should e.g. work on being more honest and empathetic, rather than deciding to become an introvert or an extrovert (a personality issue). And in heaven (or rather the new heavens and the new earth) we will be different because our characters will be perfect, but our personality will stay the same (if we want it to).
This verse seems a bit relevant, 1 John 4:7: "Dear friends, let us love one another, for love comes from God. Everyone who loves has been born of God and knows God."