Either you understand by it a person, in the common sense of an intelligent or self-conscious being;--or, 2.

a thing with its qualities and properties;--or, 3.

certain powers and attributes, comprised under the word nature.
If we suppose the first, the contradiction is manifest, and you yourselves admit it, and therefore forbid us so to interpret your words.
For if by God you mean Person, then three Persons and one God, would be the same as three Persons and one Person.

If we take the second as your meaning, as an infinite thing is an absurdity, we have three finite Gods, like Jupiter, Neptune, and Pluto, who shared the universe between them.

If the latter, we have three Persons with the same attributes; -- and if a Person with infinite attributes be what we mean by God, then we have either three Gods, or involve the contradiction above mentioned.
It is unphilosophic, by admission of all philosophers, they add, to multiply causes beyond the necessity.