The words sacred or holy are sometimes used interchangeably and are often misunderstood to mean "important" or "special" instead of "set apart" and "pure."
According to Websters 1828 Dictionary (the more accurate definition given the spiritual context- Christian and beyond), sacred means "...separated from that which is common, vulgar, polluted, or open... or Holy." Holy, means "Properly, whole, entire or perfect, in a moral sense. Hence, pure in heart, temper or dispositions; free from sin and sinful affections. Applied to the Supreme Being, holy signifies perfectly pure, immaculate and complete in moral character..."
Most religions have sacred books that provide teachings or doctrines associated with the religion. These books are "set apart," from other books published and associated with the religion. There is a deeper connection to these books over the others.
For Christians this book is called the Bible. Muslim peoples have another book, they call the Qur'an. Jews call their book the Torah. Similarly, the Book of Mormon is also considered as a sacred book in Mormonism.
Some religious people deem specific places sacred because of their mention in the sacred books. Jerusalem is seen as sacred by Judaism, Christianity and Islam. Mecca is sacred in Islam, and Ise Grand Shrine in Mie Prefecture is sacred in Japanese Shinto. In Hinduism the river Ganges is seen as holy.