good muslim and bad one

how can we distinguish between good and bad muslim ? i'm sure most of you would choose general behaviour as criteria ,i would agree but the problem is that alot of muslims give no attention to this point, and think they have the right to do whatever it taste funny to them regardless of what the others ( specially non muslims ) would think about them and the judgement they would make .they're not aware of the responsability of being muslim ( and it's really a huge one ) ,we have two kinds of irresponsible muslims here , first group who are careless about islamic principles and teaching and very neglecting of the religious side of life ( and that's a kind of extremism simply because it's a dangerous deviation from the right path) , and a second group who claim having the monopoly of truth and who despise other muslims and consider all non muslims as ennemies . the fact is that both groups are extremists and have done a lot of damage to the image of islam , nobody can nominate himself judge of other people deeds , but what can a good muslim do is to preach the word of god with good manners with full respect of others lives , customs and confessions ,we should never forget that prophet mohammad ( may peace be upon him ) had suffered opression , torture , exile , plots ,illness to convey the pure message of mercy of allah (swt) to all mankind and he never expressed hatred and disdain toward others even his ennemies and prisoners of war were treated with mercy ,we are in a real need to reread our prophet's tradition and his way of dealing with others , but saying all that i'm not pessimistic , there is ( hamdu lillah ) a lot of our brothers and sisters who are making a lot of efforts to show the real message of islam and who are saying to non muslims " don't judge a divine message by the behaviour of its people , go to the sources , make an individual effort and look for the truth regardless of what the media is saying , all i'm asking you to do is to be a sincere truth seeker ".