Human affection, so beautiful in its apparent simplicity, really depends upon a treasured host of observations of the actions of our friend. So it is also in the case of our relation to God. It is because we know certain things about him, it is because we know that He is mighty and holy and loving, that our communion with him obtains it peculiar quality. The devout man cannot be indifferent to doctrine, in the sense in which many modern preachers would have us be indifferent, any more than he can listen with equanimity to misrepresentations of an earthly friend. Our faith in God, despite all that is said, is indissolubly connected with what we think of Him. The devout man may indeed well do without a systematization of his knowledge-though if he be really devout he will desire just as complete a systematization as he can possibly obtain-but some knowledge he must certainly have.
from “What is Faith“ by J. Gresham Machen pg 75