God is a proctor. Life is the exam. The purpose of life is to see how far you can go till the end. Its to see if you can handle life. The more challenges you get in life the more stronger you get. The more challenges you get is because God knows you can handle it. Don't think about the mistakes you did in throughout, learn from it and complete your task. As long as you complete it and tried you haven't failed. Show them you can be strong.
