Berkeley's Abductive Argument for the Existence of God

If we accept Berkeley's argument that material substance is an illusory absraction, then how do we explain where our ideas come from? There are 3 options: (1) other ideas (2)ourselves (3) some other spirit.

In par. 25 he rules out (1) with this argument:

(1) Ideas are manifestly passive—no power or activity is perceived in them.

(2) But because of the mind-dependent status of ideas, they cannot have any characteristics which they are not perceived to have.

Therefore,

(3) Ideas are passive, that is, they possess no causal power. (http://plato.stanford.edu/entries/berkeley/#3.1.3)

He rules out (2) with the observation that although we have some power over our ideas, for example we can imagine what we will, we do not have control of our sensory ideas (remember back to Locke's example of looking at the sun). However, Berkeley does not conclude from this that material objects must exist, but rather that "there is therefore some other will or spirit that produces (our ideas) (par. 29).

Berkeley corroborates this claim with evidence from the orderly and coherent nature of our ideas. They are not excited at random like the ideas generated by human willing, but are "a regular train or series, the admirable connection whereof sufficiently testifies the wisdom of its author" (par. 30).