I have attached both Piper's critique of Ayn Rand's objectivism, and Chamber's review of Atlas Shrugged (Rand's best-known novel) from National Review (1957). Piper is a fan of Rand's, but with grave reservations. Chambers was scathingly critical of Rand, partly because he knew many political conservatives would be drawn to the surface level arguments she makes, but might miss (or worse, be attracted to) her basic philosophical argument.
An excerpt from Chambers:
Nor has the author, apparently, brooded on the degree to which, in a wicked world, a materialism of the Right and a materialism of the Left first surprisingly resemble, then, in action, tend to blend each with each, because, while differing at the top in avowed purpose, and possibly in conflict there, at bottom they are much the same thing. The embarrassing similarities between Hitler's National Socialism and Stalin's brand of Communism are familiar. For the world, as seen in materialist view from the Right, scarcely differs from the same world seen in materialist view from the Left. The question becomes chiefly: who is to run that world in whose interests, or perhaps, at best, who can run it more efficiently?
Source: http://www.nationalreview.com/
John Piper:
Ayn Rand’s devastating criticism of altruism missed the point of Christian mercy.She could only conceive of mercy in terms of our sacrificing our greater values to lesser ones. The Christian sacrifices no values in blessing those who curse him, nor is his behavior causeless or aimless. It is an achievement of his own dependence on and love for the merciful God. It is caused by God’s mercy, and it aims to transform the enemy into one who treasures God above all things. It is thus a self-benefiting act, compounding, as it does, the joy of the believer.
In short, Ayn Rand has no place for mercy, whereas Christianity has mercy at its heart. Why was there this conflict here? I think it was due to Rand’s thoroughgoing immanentalism: the complete rejection of a divine or supernatural dimension to reality. If she was right in her atheism and naturalism, then I think her system was consistent at the point of demanding only justice.
But if Ayn Rand was wrong about God, if he exists, and, as St. Paul said, “made the world and everything in it . . . and is not served by human hands, as though he needed anything, since he himself gives to all men life and breath and everything” (Acts 17:24), if such a God exists (and Ayn Rand offered no argument to the contrary, only the assertion),then a radically new dimension of reality must be reckoned with and a corresponding new value should guide man’s behavior.
The new fact of reality is that God cannot be traded with as a man. There is nothing that man can offer to God that is not already his. You cannot exchange value for value with one from whom you have life, breath, and everything. You must, as a creature, own up to your total dependence on mercy and be content with it or, by an act of irrational rebellion, evict yourself from the realm of reality and try to live a contradiction.
Source: http://www.desiringgod.org/