Does the Saint Germain Foundation qualify as a church? That’s the story the listing agent sticks to in her description of the property for sale on the corner of Greenbriar and Portsmouth. As a qualifying religious institution, it’s exempt from local property taxes. The Illinois-based group, founded by mining engineer Guy W. Ballard in 1934, is selling its longtime Houston home across Greenbriar from the Shepherd Plaza shopping center and worldly-goods discounter Tuesday Morning. According to followers of Ballard’s teachings, the organization’s founder had previously completed earthly stints in the person of Achilles, Alexander the Great, Kings Richard I and Henry V of England, and George Washington; in 1939, in lieu of dying, he became Ascended Master Godfre. The 3,000-sq.-ft. home at 3700 Greenbriar was built a year later.