This Muslim condolence letter is written with sympathies from the Islamic faith.
Dear {Recipient},
I was terribly sorry to hear about the passing of {the deceased}. While we know that all people are given to us by Allah for but a limited time, it is still difficult to accept the death of a loved one.
While we loved {the deceased} dearly, whatever Allah takes away or gives belongs to Him. Everything has a fixed term in this world, so we must be patient and content. I hope that you can find solace in the truth of faith in this difficult time.
Know that my thoughts are with you.
Peace be upon you,
{Sender}