The word "Zion" appears 53 times in the Book of Mormon, a key part of the Latter Day Saint canon, and 268 times in the LDS Church's version of the Doctrine and Covenants, a part of its canon consisting of what members believe to be modern-day revelation and written down by Smith mostly in the 19th century. Following the disappointments and strife which took place in Missouri during initial attempts to establish a "City of the Saints" in the region, the concept of Zion evolved to encompass a less geographically-specific idea similar to the orthodox Christian concept of the "ekklesia" (See Ecclesia (Church)) or community of believers regardless of location. This concept is hinted at in such scriptural passages as the following: "Therefore, verily, thus saith the Lord, let Zion rejoice, for this is Zion—THE PURE IN HEART; therefore, let Zion rejoice, while all the wicked shall mourn."