This Malignant Phantom

If this be true [that nature is self-sufficient], in regard to the essential nature of
theological ideas, how much more powerfully will it hold upon every
sectarian modification of the subject. If pure theism be independent
of morality, and morality independent of that, because it rests upon
the relations and the properties of human life, then it will be easy
to conceive that the subordinate descriptions of sectarian theology
must be still more unconnected with the present subject. The
character, however, of all the gods of antiquity, is, of itself, a
sufficient consideration to exclude them from any participation in
the concerns of an exalted virtue. The Jewish God commands theft and
murder; he puts a lying spirit into the mouth of his prophets; he
repents and grieves for his past conduct; he is a God of fury, wrath,
and vengeance. These actions and qualities are all attributed to him
in the Old Testament! Is it possible that any man of common sense can
believe, that moral principles which are so important to the best
interests of human society, should be placed upon such an immoral and
vindictive foundation? Can any one imagine that a being, so destitute
of moral justice and benevolence himself, could serve as a solid
basis on which to rest these qualities in human nature? No, this
sectarian God, this malignant phantom of former ages, this compound
of weakness and wickedness, is calculated to subvert all moral
principle, both in theory and practice, and present the moral world
in the full exercise of the most detestable passions.

 --Elihu Palmer (1764-1806), Principles of Nature; or, A Development of the Moral Causes of Happiness and Misery Among the Human Species