Discourses upon the Existence and Attributes of God

5. Consider, that the knowledge of God, in regard of the manner of it as well as the objects, is incomprehensible to a finite Creature. So that tho we cannot arrive to a full understanding of the manner of Gods Knowledge, yet we must conceive so of it, as to remove all imperfection from him in it: And since it is an imperfection to be changeable, we must remove that from God; the Knowledge of God about things past, present, and future, must be unconceivably above ours: His understanding is infinite, Psal. 147.5. There is no number of it; it can no more be calculated or drawn into an account by us, than infinite spaces which have no bounds and limits can be measured by us. We can no more arrive, even in Heaven, to a comprehensive understanding of the manner of his Knowledge, than of the infinite glory of his Essence; we may as well comprehend one as the other. This we must conclude, that God being not a Body, doth not see one thing with eyes and another thing with mind, as ⟨p. 214⟩we do; but being a Spirit, he sees and knows only with Mind, and his Mind is himself, and is as unchangeable as himself; and therefore as he is not now another thing than what he was, so he knows not any thing now in another manner than as he knew it from Eternity: He sees all things in the Glass of his own Essence; as therefore the Glass doth not vary, so neither doth his Vision.

3. God is unchangeable in regard of his Will and Purpose. A change in Purpose is, when a man determines to do that now which before he determined not to do, or to do the contrary; when a man hates that thing which he loved, or begins to love that which he before hated: When the Will is changed, a man begins to will that which he willed not before, and ceaseth to will that which he willed before: But whatsoever God hath decreed, is immutable; whatsoever God hath promised, shall be accomplished; The Word that goes forth of his Mouth shall not return to him void, but it shall accomplish that which he pleaseth