what subjects do you avoid in letters to friends and family ?

Me I guess I avoid mentioning religion or politics to people who are my pen pals and I really dont know that well . However people that I do know well I try and write cheerful and uplifting letters and certainly not ones that I am guessing will offend .However the mere mention of religion to some people gets them in an upraoar and why Im not sure other than they seem to think that person writing said letter is trying to stir something in them for a debate . Now as for me I try not to dabble in the debate of most things and would probably say something to the effect of well that is debatable and leave it at that .Im really sorry I will finish this blog later . I m headed to bed because I dont feel well today . Have a great and wonderful wknd and day folks .