I was looking at the September 2015 issue of the Watchtower, which, unlike the simplified and study editions, appears to be aimed at non-JWs. A couple of articles caught my eye that quote biblical sources which are somewhat less than convincing to a non-believer.
Firstly 'What do Jehovah's Witnesses Believe?' says that the core belief is that 'all scripture is inspired of God and beneficial'. Leaving aside questions such as just how beneficial the advice on the appropriate severity with which to beat your slaves is, I noticed that they make it clear that this is a direct quote from the bible (Timothy). So, hang on, - JW's believe the bible is divinely inspired because the bible says it is divinely inspired? I think their obsession with biblical quotes has caught out the WT here.
The second article is entitled 'Bible Questions Answered' and deals with biblical prophecies. Essentially it is saying that because some biblical prophecies have been fulfilled then we can be confident that the remaining prophecies (Armageddon etc) will also come about. OK - so what evidence do they put forward to support their claim that prophecies have been fulfilled? Well, they use Luke where it says:
"However, when you see Jerusalem surrounded by encamped armies, then know that the desolating of her has drawn near. 21 Then let those in Ju·de′a begin fleeing to the mountains, let those in the midst of her leave, and let those in the countryside not enter into her, 22 because these are days for meting out justice in order that all the things written may be fulfilled."
In other words, if you see a city besieged by bloodthirsty armies don't go there. And the WT goes on to argue that because those early Christians weren't daft enough to ignore this sound advice and so survived by heading for the hills we can therefore be sure that all prophecies in the bible will come true so get yourself down to a Kingdom Hall pronto.
If that's the best they can come up with it's no surprise that there is little growth in developed countries outside of births. I just wonder if the people writing this stuff ever have moments of doubt when trying to put an argument together.