What word are you referring to?
The book of Mormon? The Koran? The Catholic bible? The Protestant bible? The Ethiopian canon?
If God preserved his word, why is there no concrete way of knowing which canon is the correct one? Why aren't any "originals" in existence? Why are the oldest manuscripts from the 4th century (Sinaitic and Vatican) and yet even those differ from each other?
Even the Watchtower admits (albeit indirectly)that the bible is not trustworthy or free from error as they have made changes to passages such as :
John 7:53-8:11;
Mark 16: 9-till end of chap.
1 John 5:7,
John 1:1;
Hebrews 1:6 and many others.
"God" hasn't been able to produce a book free from errors, spurious passages, and not even a clear canon to believe in. God wasn't able to protect his word from errors and contamination. This speaks volumes about god's interest in humans to be saved and to be known by him.
Religion was invented for people who cannot accept the fact that we are alone in the universe and refuse to accept that we will someday return to inexistence.