(CBS News) Cyntoia Brown-Long made headlines when she was sentenced to life in prison at age 16 for killing a man whom she says picked her up for sex. Then-Tennessee Governor Bill Haslam called her case "tragic and complex." She was granted clemency earlier this year, after spending 15 years behind bars.

Now free at 31, she shares intimate advice for her 16-year-old self as part of our series "Note to Self."

Dear Cyntoia,

I know you're anxious and you feel alone right now, but I want you to know that God hears you.

You don't have a driver's license, you haven't voted or even made it to prom, but today you're in juvenile court praying that you will not be tried as an adult. And although you will be told that you're going to die in prison, I'm here to tell you that's a lie.

A wild swing of events is about to take place that will cause you to question whether God even exists. But just keep your faith and trust me when I say, He hears you.

I know right now it seems like all you ever hear is talk of what a horrible person you are. You've been called a whore, a murderer, incorrigible. But I want you to know that you are so much more than the worst thing that you've ever done.

I know that as a little girl you felt like an outcast when kids talked about your hair or skin color. And this moment is no exception. But know that a day will come when you could care less what people think of you.

There is a fire that burns inside of you that will eat up any obstacle that dares to stand in your way. You don't realize that yet, but you are bigger than anything that anyone tried to do to hurt you.

Yes, there will be many lonely nights that lie ahead of you. You'll spend some time believing that the world is against you and that you'll never be happy again. You'll be exploited and mistreated by people for years to come, including your own biological mother. And you'll have your hopes of freedom dashed repeatedly. They'll attack your character, your family, your marriage, your faith. But none of what they have to say defines your self-worth or your happiness. Stay focused on your calling.

You will learn that there are many people from all parts of the world who support you, who believe in you. You will know once again that happiness is meant for you, too! And through the people who mistreated you, you will know forgiveness. And it will bring you a freedom that you can enjoy even in prison.

Most importantly, though, you will forgive yourself. It'll be hard, and it'll take many years, but you will love yourself again. 

You can't see it now, but God is going to use you in a mighty way. Through you, He will give a voice to the voiceless. You will speak up at every opportunity to encourage justice, freedom, and mercy for the oppressed.

And that prayer you prayed, the one where you promised God to tell the world about Him if He freed you? That will come to fruition as well. You'll one day get the chance to tell the world every detail of your journey through the system and how God freed you from it all.

Never forget what I told you from the beginning: God does hear you.