married to a jehovas witness

[Clueless Morgan]

Doesn't work, especially on the new convert. All they do is sink further into the beliefs of the cult.

I agree. If you're really aggressive you can have the opposite effect to what you're intending and actually drive the person deeper into their beliefs.

Depending on what kinds of things they're being fed by their cohorts, you could be playing into the stereotype of the angry atheist (or whatever other stereotype you might fit into), or playing into their made-up persecution complex: "See? What did we tell you would happen? You're being persecuted, so we must be preaching the truth!" In either case, you could be affirming their expectations.

That's why Boghossian suggests small doses in non-confrontational conversations - you can sneakily undermine their claims and introduce cognitive dissonance without (hopefully) getting them to auger in and refuse to have the conversation again.