We live in group. Society is a very big group. We cannot manage affairs smoothly without following law which is for benefit of the whole society.
There are some rules for even small groups. Every association, club, institution and even family have rules. You make some rules even if you are single. For example, I have made the rule that I shall take breakfast after bath, then leave for office, buy necessaries on way back, work on Boddunan for some time, then take dinner and stroll for some time. Then watch TV and sleep therafter.
When you need rules even for your daily routine, it is obvious that we need law for whole country also.
Yes, I agree that for the smooth functioning of our society we as a member of the society should try our level best to maintain law and order in our lives so that it helps us to leave in complete peace and brotherhood...