Answer:
Creating lists does seem appropriate as they can relieve stress and keep the mind occupied. When dealing with grief, some people fall into a depressive mood and keeping lists can help prevent that.
Arnold's father's way of dealing with grief may seem helpful to him at first, however with time this can bring more harm than good, especially if he is already a heavy drinker. The amount of booze he is consuming may be enough to make him dr*nk and this can be dangerous as he won't be fully aware of what he is doing.
Arnold's mother's way of dealing with grief will be helpful to her throughout grieving. Many people pray to God whilst grieving and this can keep the mind and soul at peace. This method can also be used as a way of connecting with the deceased's soul through God and for many people, this is a reliever that their loved one is in a better place.
In conclusion, there is no 'right' way of grieving but there are safe ways which are recommended to be used. For example, methods which keep the mind at peace are much more effective than drinking as there are obvious long-term benefits but drinking does not have any.
Expand on some paragraphs where needed but here is a draft for you.