Rev 12:10-11 (KJV1611 Edition, e-sword.com ):
And I heard a lowd voyce saying in heauen, Now is come saluation, and strength, and the kingdome of our God, and the power of his Christ: for the accuser of our brethren is cast down, which accused them before our God day and night.
11 And they ouercame him by the blood of the Lambe, and by the word of their Testimony, and they loued not their liues vnto the death.

Does it seem to be fair that:

If God's people can overcome Satan/Devil "by the Blood of the Lamb and by the word of their Testimony"
then one's Testimony is of significance.

Here is my Testimony of overcoming Satan/Devil:

Since 1975 (yes 34 years) or so I've been an invitation worker in my current church. I counsel those coming forward at invitation. I've been there when some 280 people were Saved by Jesus. 180 such times I have had a NIV in my hand. about 80 times I had a KJV in my hands. Sorry, but there are Preachers out there & Deacons, Evangelists, Missionaries, Sunday School teachers, and mothers and fathers because of the NIV (yes and convicts, drunks, and homosexuals /well, one died of Aids at age 34/, and other misses).

I believe the KJVs are Bibles, but so are NIVs.