When Christ Jesus taught his followers the parable of the tares and the wheat, he was showing mankind how to reap a harvest of spiritual good. He was explaining the duality of the so-called human mind, wherein good and evil seem to exist side by side, and expounding the Science of salvation, which demonstrates the nothingness of mortality and the immortal nature of good.
Mary Baker Eddy, the Discoverer of Christian Science, writes in "Science and Health with Key to the Scriptures" (p. 72), "Mortal belief (the material sense of life) and immortal Truth (the spiritual sense) are the tares and the wheat, which are not united by progress, but separated."
Christian Science reveals God, Spirit, as All, the source and substance of all spiritual consciousness. It demonstrates good as one Mind, never divided into many minds but including within the vastness of its infinite comprehension every manifestation of good. Existing eternally in one universal unity, or wholeness, good never wanders from the control of the one intelligence, God. The fact that God is the only Mind bases the great harvest of spiritual healing with which Christian Science is blessing mankind.