ValueOur identity in the sense of what about us we look to to say "I am valuable" should be answered by Christ. He is our righteousness, and all that we do, apart from him, are as worthless rags. If we find value in some aspect of ourselves in and of ourselves then we are not getting to the source of the value. If I "have not love, I am nothing" 1 Corinthians 13:2, and "Beloved, let us love one another, for love is from God, and whoever loves has been born of God and knows God." 1 John 4:7. More than this, it is his righteousness which we have, and it is not our own doing, rather, we have this treasure in fragile jars of clay. This is the way that I hear identity most often spoken of in sermons and the circles in which I read (See here).
PersonThe second sort of identity, which I want to distinguish from the first, is how the person is personality-wise. Not what their character is like, nor what they do, but who they are deep down. This may be exhibited in their character and actions, but it won't necessarily be.
This identity we also, in a sense, find in Christ. In him we are redeemed to live as we were meant to live. Not only does this mean that we get to be who we were meant to be as humans: to glorify God and enjoy him forever, but also that we get to be who we were meant to be as ourselves.
However, it is not as though this identity is not there apart from Christ, rather, we deny it. This kind of identity does not involve our sin nature, but because of our sin nature it doe snot come out as it ought, for it depends on the general human nature as a being who is made to glorify and enjoy God forever. Thus we cannot be our true selves apart from being true humans, i.e., glorifying and enjoying God. This is who we ought to be, who we are in Christ, who we will be in heaven, and who we would have been apart from the fall. It is not the self we deny, nor the life we lose, for the self we deny and the life we lose are neither a true self nor a true life, but a life and self twisted by sin. The self does not change, but the one who owns and rules it does.
This self, however, is not where we find our value, for it has value only insofar as it displays the glory of God, that is, its value is Christ. It does, however, have value, though that value is the same in all people, and, though defiled by sin to varying degrees, all which are sanctified will be equally God displaying when they are sanctified. This self will most be itself in worship of God, but various selves may do this in various ways, for the Church is a body with many members, and not all members have the same function.