You are not going to get through to them, because their Filthful and Disgraceful Slavebugger has done such a perfect job of making everything else look like it's from Satan.
Now, objectively, according to their own definition, faith is the assured expectation of things not yet beheld, but that there is evidence that it is coming. All they have to do is to fabricate the "evidence" out of whatever is going on in the world, and that backs up their "assured expectation". Now, throw in a little truth, and it all falls apart. First, anyone that digs hard enough is going to find that the witlesses were an attempt to settle the argument about when the end was coming--which was raging during the early and middle 1800s. The first date was 1874, given in 1872 (about the same lead time they have been working with ever since). So, if anyone were to look at this, there would no longer be "assured expectation" of the end coming in around two years.
As if this weren't bad enough, even if the religion started on the right course, how is anyone going to decide whether it has stayed on that course? Remember, though Russell started the idea that the end was coming in a few years (to settle the arguments raging about when the end was coming), Boozerford was the one that got many of the other stupid doctrines going. He banned birthdays and holidays, started everyone to have to do field circus, and closed heaven off in 1935. And, every time they get new leadership, one has to ask whether they are really abiding by the previous leadership, or are trying to hijack the cult for themselves. Raymond Franz tried to set the cult back to the Bible, but was put out of the whole religion for doing so.
Now, is the Bible they use even accurate? One has to ask whether Jesus was misunderstood. One also has to ask whether the writers who wrote the Gospels could have remembered those details 40-60 years after they happened, or if Paul (who was mistaken in taking it literally) corrupted their memory (intentionally or not). Then, were they penned accurately, or were there original transcription errors? Were they kept faithful to the originals when the Catholic monks wrote them down, or did the Catholic church alter the texts? And did the monks make transcription errors? How are they to be corrected?
And, even if the Bible was written down accurately, is it really the truth, or is it the Supreme Scam? Did God really put those prayer answerings in the Bible to give us a taste of what to expect, or did He do it in lieu of actually answering anything these days? What's with all the massacres in the name of God of people that were minding their own business or God punishing those trying to serve Him but that made a mistake or a series of mistakes? Or praising those who destroyed more value in the name of a High Sacrifice, or that killed tens of thousands of innocent people for minding their own business?
And, the biggest issue of all, did God really have righteous standards, or did He merely prohibit independent thinking so everything we did was what He told us to? And, did God make up the Original Sin doctrine so He could then subject Jesus to unnecessary suffering to make Himself look like a damn hero when in fact He was the villain? (On top of trying to get a pretext for extorting obedience out of us.)