The very question would strike most people as odd. Not only is Truth—understood in Christian Science as God— immeasurable. But the spiritual understanding of this fact is invaluably practical.
The infiniteness of God and the fact that His man and universe, being like Him, are matterless is the axis around which Christian Science revolves. Truth fills all space, is All, includes no physical objects, expresses itself in uncountable ideas. Hence, "Allness is the measure of the infinite, and nothing less can express God," Science and Health with Key to the Scriptures, p. 336; writes the Discoverer of Christian Science, Mary Baker Eddy.
Man is the idea, or reflection, of Truth and is just as immeasurable as Truth. Hence it is illogical, in Science, to speak of the size of man or try to measure the good that belongs to man. Mind, Truth, Spirit, Life—God—is reflected by man but is not in man, in any sense that would suggest God's or man's finiteness. Mrs. Eddy explains: "IN. A term obsolete in Science if used with reference to Spirit, or Deity." ibid., p. 588; It would not even be a useful analogy to say that "Life cannot be put into a corporeal personality any more than a whale can be put into a sardine can." Both whale and sardine, as sea creatures, at least belong to the same set of items. But Mind and matter are entirely different in kind—opposites, in fact, that can never get together.