I do appreciate one thing about Heinlein's portrayal of God, though: he treats it like a real thing.
One of the things that I find most deplorable (and baffling) about the way I perceive a great portion of my peers evaluating religion is that they treat it like an idea to be accepted or rejected. I suspect that this is one of the nefarious side effects of the idea of freedom of religion. It is obvious that everybody has the right to choose their own religion (and accept the consequences thereof, which may include summary execution depending on your locale), but somewhere along the line I perceive that people have gotten this idea that religion is something made up. With surprising frequency in the past couple weeks (and for my whole thinking Christian life) I've run into the attitude that "I just can't believe God would be like that" or some inconsequential variant thereof. The nature of God is not an idea to be built; it's a truth to be discovered. Saying "I just can't believe God would be like that" is every bit as ridiculous as Einstein refusing to believe in quantum mechanics, or the Church refusing to believe Copernicus.
Interruption: "I just can't believe God would do that" is a valid criterion by which to judge events on a spiritual plane, once the nature of God has been determined to a reasonable degree.
But, on the other hand, if that is what you're looking for and refuse to acknowledge it for no better reason than "I just can't believe it" then you should at least have the decency to admit that you're deceiving yourself through denial. Take hell, for instance. I don't understand the nature of hell particularly well (nor do I intend to waste much skull sweat over it, since I do understand it well enough to know that what hell is or isn't has nothing to do with me), but it's amazing the number of times a conversation with someone who's wondering about Christianity comes to the point where Someone says, "I just can't believe in a God who would create hell." That statement betrays a fundamental unreadiness to believe in God: because you're still treating God like a picture you can customize, instead of a [metaphorically] living, breathing individual who is what he is whether you like it or not.
Now sometimes someone will say that (or an equivalent statement) and actually be trying to point to a contradiction that goes something like this:
Axiom: God is good (or loving, or merciful, or whatever alleged attribute of God you want to include).
Axiom: Hell exists.
The proof is oftentimes that spotty, too, since if you try to pin down the intermediate steps you usually run into a question of definitions: either "what is good?" or "what is hell?" I'm only aware of one workable definition of the former, and it's one that Someone usually finds unsatisfying (I'm sure Watson felt the same way about Holmes' "when you've eliminated all other possibilities" axiom). As for the latter, I don't know enough to answer the question very well and I doubt that many other people do either, which makes it silly to use it in an attempt to catch Christianity in a contradiction. (I'm not aware of the Christian God ever having actually been caught in a contradiction: so far as I know all anybody has on him are issues in which there is no contradiction, or issues in which there might be contradictions but nobody's really very sure. In the face of a record where all the questions we can deal with turn out in God's favor, I'm not inclined to lose sleep over the question marks.)
What really gets me about this issue is that it often seems to be the last obstacle to friends who "agree intellectually" with Christianity but can't bring themselves to "believe." I strongly suspect this to be drawing a dichotomy where none exists. What that must really mean, I think, is that someone believes Christianity but can't bring themselves to act like a Christian - or, more likely, doesn't know what acting like a Christian means. After all, there's nothing to "believe" about Christianity other than the question of "true, false, or not sure." If you "agree intellectually" with Christianity you must have checked the "true" box; you "believe" it definitionally in the same way that you "believe" in quantum mechanics.
The tragedy of it all is that people have been conditioned to think that "believing" a religion is the truly important part about it. Maybe that's true with other religions; I don't know, but that's not what Christianity is like at all - and if someone who "agrees intellectually" with it has missed that point, then his or her study of the religion leaves out a crucial point. Believing Christianity really is like believing quantum mechanics. The utility of quantum has nothing to do with its truth or falsehood; the utility is in the implications. Believing in quantum mechanics doesn't enrich your life any: seeing that quantum mechanics implies lasers (and a million other things) does. Acknowledging the theory to be true doesn't get you anywhere; you have to figure out how to apply it. Similarly, the meat of Christianity - I might almost call it the point - is in its implications for your life. Those implications depend upon acknowledging the "theory" to be true, but they are not the same thing, and the leap from Christ's death to invincible joy and contentedness (and a million other things) is about as obvious as the leap from Copenhagen to supermarket scanners. The relationship is there, it's just work - very worthwhile work - to figure it out. But people who keep looking for that relationship by asking "do I/can I believe this?" are going to be eternally frustrated. What they should be asking is "I believe this: what does it imply?"