Why does Mill call utilitarianism a "more profoundly religious [doctrine] than any other"?

Utilitarianism is an ethical theory that was born in the eighteenth century and whose creator is called Jeremy Bentham. Utilitarianism seeks the greatest good, for the greatest number of people, that is, seeks happiness for all people.

John Stuart Mill, adept to this doctrine, argued that the human being is in a constant search to achieve the greatest pleasure. Mill placed spiritual and intellectual happiness in the first place and, in the background, bodily pleasure.

He argues that "utilitarianism is more profoundly religious [doctrine] than any other" because this doctrine is aimed at seeking the greatest happiness not only of one's own but also of one's neighbor. The pleasure and suffering that is related to God's love and punishment appears in this search for happiness. If he performs good deeds, he will be rewarded, but if he does bad deeds, he will be punished.