SpiceItUp, Turn the tables on him.Tell him its not about disproving the Bible on any point,but,for him to prove with the Bible his many points.For example:
Interpreting the Bible: Ask, can a person read the Bible on his own and come up with the truth? If he says no,then how are the proofs established.If he says yes,then tell him that the Society teaches that it is the only one that has the right to interpret the Bible.On what valid basis can the leaders make this claim?
Also,Scholars themselves have always been at odds with proving and disproving the Bible on many points of doctrine and belief systems.So, the question is a trick question that should be placed back in his court to prove to you his points of belief.
When using the NWT.he can be challenged by using the "Kingdom Interlinear of the Greek Scriptures,1969 and 1985 versions by the Society along side of the NWT. and he will see how the Society has changed the Greek words to fit their interpretations.
If it is any help, the society says Jesus died on an upright stake, pages 1149,1150.in the kingdom interlinear, however , the How Can Blood Save Your Life Brochure show the christians dying by being executed on crosses. Blueblades