No, being who you are isn't really a sin, but then again, it is. We live in a society that drowns children in this ideology to be who they really are, to not let anyone tell them differently. We want them to be independent, make up their own mind, do their own thing and not let anyone tell them that it's not okay.
But who are we, really? At the core of who we all are is pretty gross. We are truly evil creatures, and it begins as children. We tell lies, we're selfish, we're mean as a snake. We hate the people who raised us, we physically hurt others for making us mad, we use our words to bring others down. We let jealousy overtake our relationships, as well as lust, not to mention sexual immorality. We hate, we covet, we curse the God who made us. Some of us kill, spill blood, break down the body that was made just for our own souls. We are vile, nasty things. All of us. This is the core of who we are. This isn't something that is disputable, this is fact. Read a psychology book, it's in there.
Is this what you want to teach your children?
When Christ preached his most controversial of sermons, he said that we as Christians should die to ourselves. We read that now and think "Dang, Jesus, cool it down!", but it's totally true. We literally are called to make every effort to kill the human in us. We are told to take up our own crosses (think electric chair, a killing machine) and follow Jesus, no questions asked. Now, many lessons can be taught from this one statement, but to me Jesus really is saying this:
Today, when you accept me as your Lord and Savior, you are no longer you. You are me. You must eat my body and drink my blood. You must take up your own cross, carry it on your back, then die hanging from it. And then, you must become transformed as I did. When you decided to listen to Satan over God all the way back in the Garden of Eden, you decided who you were. Not anymore. You are now light of this Earth. When you seek me and stay in my word and let me take you through this process of transformation, you gain goodness, patience, joy, peace, happiness, love, self-control, kindness, and gentleness. You aren't you anymore, you get to be me.
If the Bible says it's a sin, it's a sin. I don't care if you were "born that way" or if you think "it's not really bad for you", you check absolutely everything you do with that book and with God. Because who you are deep down is not who you want to be, I promise. Prison is full of people who were being who they really were.