Neville's answer to theology, and it is a rule about method rather than a claim about doctrine. One cannot discover the true character of God by investigating or discussing him. One must let him save; then one knows. He is a savior in every sense of the word, so one must let him save - and only then does one really know the character of God. You can discuss him, investigate him, from now till the ends of time, but you will never really know God. What makes it usable rather than pious is what he does next: the test is specified and it is not a spiritual one. Say I am before you say I am this or that; if that is God and he is a savior, then test him - see if he really can save me from my present restriction in this world. So the knowledge of God's character is obtained by asking him for something and watching what happens. Also at 1235.