Having self-esteem means having faith or believing in yourself. 

The Bible teaches us that faith is the assurance of things we hope for and the certainty of what we do not see. In other words if you can see it, then faith is no longer required.

The Apostle Thomas didn't believe that Jesus had resurrected until He saw Him, and Jesus responded by saying, you believe because you see, blessed are those that believe without seeing.

After Jesus ascended to Heaven, He sent down His Holy Spirit to guide us and teach us the truth. The Holy Spirit can not be seen with the natural eye, that's where we require faith to make the connection with Him through our spirit and through prayer. 

In the same way that we need faith to have a relationship with God (since the Bible says that without faith we can not please God). We also need faith in ourselves, which basically means believe in yourself even though you don't see any reason to do it. Believe in the person you can become.

Jesus said, we are the light of the world. That is not a small statement. If you're walking down a dark alley, everything seems dead, but once it has light, it brings life to the environment and lets everything be seen more clearly. The same with the sky at night, if you look up and there are no stars out, a dark sky looks boring, but once the sky is filled with the light of the stars, it turns into a beautiful scenery. That's how God sees us, when He looks down into the world, He sees millions of stars shining in the middle of a dark and perverse world, giving Him a beautiful scenery to admire.

A great benefit of seeking a relationship with the Holy Spirit is that your self-esteem, your joy and your peace will come from within and not from outside circumstances or by what others say or think about you.

Believe in what God says about you even though you don't see it. Have faith in God, seek a relationship with the Holy Spirit and have faith in yourself. God created you, He gave you a life so that you can enjoy it to the fullest. In Him, this is possible.

Love God, Love Others and Love Yourself.