Sometimes people base identity on what you say about yourself, sometimes on what others say about you or labels that are attached to you because of things that have happened, people you hang out with, or your interests.
We tend to find our identity in temporary things: families, friends, hobbies, likes, dislikes, possessions, successes, failures, appearance and many others.
However, if we believe that Jesus died to provide forgiveness for our sins and we accept that as a free gift and want to live our lives for God, our identity should be found in the permanent things. In God, and the things he's promised.
Knowing and believing our true identities can be so hard though! It's so much easier to believe the things that we're surrounded by.
How can we know what our identity is? Read the Bible. Find out what God says about who you are. I've started making a list of verses that help me remember who I am in Christ. You can see it here-
Which leads me into the next part. You can know every right answer, but how do you believe it? That's the hard part because it requires application and change. Some of our identity in Christ is there no matter what, like being loved and precious to God, but other parts we have to believe in order to fully reap the benefits. Like being forgiven. God forgives us, but until we're able to stop beating ourselves up and forgive us too. We have to accept that we're forgiven and move on. We have to get rid of the lies and most importantly, replace them with the truth. Read your Bible and find what God says about who you are, and when you feel the lies creeping in, read those verses to fight back against the lies.
What exactly should we look like as someone that's in Christ? Proverbs 31 and 1 Peter 3:3-4 are good examples of what a Christian woman should look like from the outside. As God changes us on the inside, and the things we believe about ourselves change, our outside actions will change. Just be careful that you aren't only changing the outside though (Isaiah 57:12). That just leads to more problems in the end because what you're doing looks good, but you aren't actually changing.
Just remember that God made you uniquely who you are. No one has the same identity as you and that's the way it should be!
Embrace what makes you you!