For example, here is a plot of the terms Lord, Jesus, Christ, and God appearing in published works between 1750 and 2008:
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And here is a plot of the terms Holy Ghost, Holy Spirit, and Heaven appearing in published works between 1750 and 2008:
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And finally, here is a plot of the term Zion appearing in published works between 1750 and 2008:
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Note the upward trend in all 3 plots coincides with the beginnings of the 2nd Great Awakening in the early 1800s, which then starts to decline by the mid-1800s. Believers of the Restoration of the Gospel of Jesus Christ through Joseph Smith, jr will also note the striking changes in these trends in years of spiritual significance such as 1805 (ascending), 1820 (ascending), 1830 (peak), and 1844 (declining). It's interesting to note the slight uptick in use of many of these terms since the late 1990s. The beginning of another upward trend?