God selected you before the foundation of the world. He picked and identified you as His own but you must do your part by in turn identifying with Jesus and His victory over the enemy. All of the benefits of being identified and selected by God can only be secured by accepting Jesus as your Lord and Savior.
When God selected you, He did so with a purpose in mind. He created you to accomplish something. He designed you to carry a solution that your generation needs. Before you were formed He knew everything about you - Jer 1:5. That should be a source of encouragement because this means that irrespective of what you have gone through or are going through, you are important. You are so important to your generation that God had to send you now.
Friend don't allow anyone talk you down or belittle you. Your destiny is secured. You are a person of significance. You came with something that your generation needs. Get busy discovering your purpose in God, developing yourself so that you can deeply yourself. Then you will fulfill your God-given mandate to be fruitful, multiply, subdue, replenish and walk in dominion - Gen 1:28.