Ask him if the GB brought back the "pyramid inch" would we be compelled to believe it again?
Ask, if Jesus selected the F&DS in 1919 (and this is no longer all the remnant), who exactly did he choose, and who chose the current F&DS in New York?
See if he knows that the current definition of Generation is a 200 year period, and why is this different to the Bibles definition of a generation?
Ask him if he has been disturbed by the incredible number of doctrinal changes over the years, then show him g70 4/22 p. 8 Changes That Disturb People:
"Yes, millions of persons have been shocked to learn that things they were taught as being vital for salvation are now considered by their church to be wrong. Have you, too, felt discouragement or even despair because of what is happening in your church? A businessman in Colombia expressed the effect the changes have had on many."Tell me," he asked, "how can I have confidence in anything? How can I believe in the Bible, in God, or have faith? Just ten years ago we Catholics had the absolute truth, we put all our faith in this. Now the pope and our priests are telling us this is not the way to believe any more, but we are to believe 'new things.' How do I know the 'new things' will be the truth in five years?"