Here are 10 tips on how to write a condolence letter and what to say and what not to say. Please accept my heartfelt condolences during this incredibly difficult time.The loss of a parent leaves a void that words cannot fill. Keep the letter as brief and as short as possible. When writing to parents, consider addressing the letter to siblings as well. "The loss of a mother leaves a void that words cannot fill. She Nearly Died After Being Denied Care. My fatherinlaw died on my 61st birthday and other family members and good friends have lost spouses, siblings and parents. When writing to parents, consider addressing the letter to siblings as well. Our prayers and thoughts are with you.