Here is just one example of JW's Watchtower changing its story...
1914 : Failed Watchtower Prophecy

1914 : Failed Watchtower Prophecy

One of the most misleading statements in Watchtower publications is that they accurately foretold 1914 to be the “start” of the conclusion of this system of things. Rather, Watchtower falsely predicted 1914 to be the “end” of the system of things, the conclusion of Armageddon and the start of the earthly paradise.

It is important to know what Watchtower preached would happen in the years leading up to and including 1914, and compare this with what it now claims was said.

	What Watchtower said prior to 1914	What Watchtowerclaimsit said prior to 1914
1	"The year A.D.1878… clearly marks the time for the actualassuming of power as Kingof kings, by our present, spiritual, invisible Lord - …"The Time is At Hand (1911 ed)p.239	"The Watchtowerhasconsistentlypresented evidence to honesthearted students of Bible prophecy that Jesus’ presence in heavenlyKingdom power began in 1914."Watchtower1993 Jan 15 p.5
2	"But bear in mind that the end of1914is not the date for the beginning, but fortheendof the time of trouble.Zion's Watch Tower1894 Jul 15 p.226	"Jehovah's witnesses pointed to the year 1914, decades in advance, as markingthestartof "the conclusionof the system of things."Awake!1973 Jan 22 p.8

The contradictory statements above help identify two critical facts:

1. Watchtower falsely predicted this system would end in 1914
2. Watchtower is not entirely honest about its history