Al R - what I do is pick a non-religious condolence message as a play safe option. I express genuine sympathy, in a non-religious way. The old adage is to avoid discussing sex, religion or politics if you are not sure of the views of your correspondent, thereby avoiding causing offence.
By avoiding the subject of religion in the first place I avoid the risk of giving offence - this is the polite thing to do (as you should always tread carefully with regards to the subject). For me to send a religious card/message would be hypocritical as I do not believe in any deity - and if the recipient knows me then they will know that to be the case and as such a religious message would perhaps indicate a lack of sincerity on my part (a bit like the American "have a nice day"). If the recipient then reads some sort of spiritual message into the words that is their choice.
My brother in law and his wife are born again Christians and tend towards the biblical on birthdays, condolences and (perhaps unavoidably) Christmas. I accept that it's important for them to do this because of their faith and that they mean nothing but the best by it. In return, they understand that scripture means absolutely nothing to me and that they are never going to make a Christian out of me! However, in this case we all know each other well enough to avoid giving/taking offence (although at first it DID irk me more than a little).
For the record, I do attend church for weddings, funerals and baptisms - out of respect for the person being buried/married/baptised, not because I believe in God or want people to think that I believe in Him (you'll note the capitialisation of God and Him out of respect for the beliefs of Christians). I do not, however, sing hymns or say prayers as again that would be hypocritical and would therefore insult other peoples' beliefs. Given my choice, I would never set foot in church again in my life (or death!) but do so out of respect for the celebrants at these services. I believe in PEOPLE not God(s) and thus direct my thoughts towards them.
I hope that answers your question.
(Edited for improved clarity - I hope!)
Last edited by moggiee; 1st Sep 2007 at 00:22.