The fact is, that we can no more dissociate ourselves from God in the matter of knowledge, (understanding by the term, true knowledge or the truth,) than we can in that of physical existence. God did not create the body, which is the inferior and less difficult work, and leave the mind to create itself. And, on the other hand, man can no more create his mental nature than he can create his physical nature. He can no more create the attributes of his mental nature, its powers or faculties, than he can create those of his physical nature. And if, in the exercise of the moral freedom with which he is endowed, he may make the effort, independently of God, to sustain them in their right exercise, the endeavor, however sincerely it may be made, will be found to be ineffectual. He will necessarily fail in all such efforts, because, in substituting the finite for the infinite, in resting upon himself instead of God, he has chosen means that are wholly inadequate to the result. The Savior himself says, "I have not spoken of myself, [that is to say, by any source of knowledge or wisdom in myself,] but the Father which sent me, he gave me a commandment, what I should say, and what I should speak." Separate from God, therefore, we are separate from the truth.
— edited from A Treatise on Divine Union (1851) Part 3, Chapter 2.