Communicate to your friends as;
when you help others, then when you are in need, some one will help you. You will have a good nature when you help others and work for social cause. You are also fulfilling your social responsibility and duty when you do social service. With out you doing any service to others, it is not right to expect help from others in future.
During social service you may learn new things and you may interact with new friends. You will see the real world and how people in the country are living. You will see the good and bad that government is doing for people and what one can do to improve the position of people.
You may think of technology, you may think of science, or other things that can help. It could lead you some where ahead in future.