From a letter from Senior Tempter Screwtape to his nephew Wormwood, who is in training to tempt Christians:
About the general connection between Christianity and politics, our position is more delicate.
Certainly we do not want men to allow their Christianity to flow over into their political life, for the establishment of anything like a really just society would be a major disaster.
On the other hand, we do want, and want very much, to make men treat Christianity as a means; preferably, of course, as a means to their own advancement, but, failing that, as a means to anything—even to social justice.
The thing to do is to get a man at first to value social justice as a thing which the Enemy [=God] demands, and then work him on to the stage at which he values Christianity because it may produce social justice. For the Enemy will not be used as a convenience. Men or nations who think they can revive the Faith in order to make a good society might just as well think they can use the stairs of Heaven as a short cut to the nearest chemist’s shop. Fortunately it is quite easy to coax humans round this little corner.
—The Screwtape Letters, pp. 126-127.