People who believe in a divine creator, trying to live their lives in obedience to his supposed wishes and in expectation of a supposed eternal reward, are victims of the greatest confidence trick of all time.
The one function that most gods seem to have in common is to give human existence some ultimate purpose - and, while it is not possible to disprove an ultimate purpose, there does not seem to be any evidence for it. This is not to say, of course, that there is no purpose in life at all: we all make our own purposes as we go through life. And life does not lose its value simply because it it not going to last forever.
Empathising with the younger children on whom the same confidence trick was being imposed, I embarked on a crusade around the neighbourhood, telling all the kids that there was no Santa Claus. This reached the ears of the father of a neighbouring family, who reproved me for spoiling it for the little ones. Spoiling it! I could not understand what he meant. To my mind, they were being made fools of, and I was only saving them from this indignity.
To say grace, knowing that people on this globe are starving, indicates a highly selfish acquiescence in the arrogantly supposed favoritism of the almighty. A really decent god-believer, far from giving thanks for the food and good health and fortune enjoyed by himself and his family and close friends, would surely curse God for his neglect of the hungry, the sick and the tormented, throughout the world.