Jesus asked, will a man light a lamp then hide it under a bushel? What was the purpose of lighting it in the first place. You also when you get born again are the light of the world. God places you on the roof top that all may see the light he has put in you and they may come to your light.
When we get born again, most often we are intimidated and do not want people to know of our commitment to God. We can even go on for sometime without letting those close to us share our new found joy. This is just a scheme from the devil so that you do not testify and more people get saved. When getting saved, Jesus Christ demands two things from you. The first one is you repent of all your sins and the other onje is confessing that he is your Lord and Savior. Confessing means you tell the whole world what God has done for you. Of course it must begin with those close to you.
As the light of the world, you have a direct assignment from God. To let more and more people know about him. Do not be intimidated or afraid. God is with you in all that you do. He will never leave nor forsake you. Most probably, those friends you are afraid of confessing to are dying for someone to come lead them to Christ. They are miserable and unhappy. You can also let the world know of tour new found faith by inviting someone who is not born again to your church so as they can get blessed.