Having one of their bibles is a big red flag. That shows previous contact with them. And I don't think they're *that* anxious to give out free bibles unless you have a commitment. You're really interested, you're studying, etc. So if you have one, you've had more than casual contact in the past.
And if you have that previous commitment and you're not welcoming them, it's a red flag. You shouldn't be offering to show them a scripture. That's a rebuttal. They want you compliant, listening to them. They want to be in the teacher role. You had past contact and they want to rekindle that. You offering to share with them is putting yourself in the teacher role and that's what makes their spidey sense tingle.
You can plain argue doctrine with them if you want, but there's a difference between chasing them away and trying to subvert them. I've always wanted to subvert them.
If you want to go one-for-one and argue with them, they'll take that from a non-JW a lot better. Because now you're one of the masses. A catholic, lutheran, baptist, etc. And they're ready to trick you. Show you something you never knew was there (like the name Jehovah) or some concept you never thought about and win you over. So they'll keep on talking.
But as soon as they get a whiff of past-JW on you, they fear you're an apostate and THAT, they want nothing to do with. You can argue against their doctrine all you want if you're a Baptist. But if you're an apostate, you can't. For some reason that is too scary.
So having an NIV, a KJV is probably better. Signals you're a worldly person.
I had a guy coming once. He even started a study with me. Not knowing I had grown up JW and I was just doing it for fun. I said I was kinda Lutheran, but I had a JW sister and aunt both out of state that I didn't see often. So, I might know a tiny bit, but not much. And I listened to him, but I questioned. I had non-JW religious books (because I was still religious at the time) - better than their concordances. And history books. I debated 607 when he brought it up. He admitted I made sense. Said the kingdom hall needed people like me who could really research and knew their stuff. I found out later that he's no longer a JW. IDK if it was because of me, but I can hope.
He even invited me to a book study one night when they were still in homes and he directed me to an elder about some of my questions about 607/1914. Me being in disguise. The coolest thing was being able to argue with an elder and tell him he was basically ignorant and full of crap to his face because he's not reading what's in black and white in the bible. And not fear any repercussions from it. If I were a JW, he'd have power over me. But as an interested one, he had none. If anything, I had power over him because he didn't want to scare me off.
It was the prophecy about 'after the 70 years has ended, I will punish the king of babylon'. When did the 70 years end? 537 BC? And when was the king of babylon killed? 2 years earlier in 539 BC? So 70 years ends. Now it's time to punish a king that's been dead for 2 years? Are you saying his soul lives on after death and 2 years later, even though he's dead, he can be punished? Can you not read AFTER the 70 years has ended, I will punish the king of babylon? I think I even insulted him. You didn't do well in grade school math, did you? It was awesome to give it to an elder!!! Respectfully without using dirty words, but not being kind either, telling him he was ignorant and watching him squirm to explain. Priceless! For some reason, that felt like a high point in my JW experiences.
If your plan is to subvert, my recommendation is play a worldly person. I hope this incident hasn't blown your cover. And this also works better if you don't live in an area where you were a JW. I left and 3 years later got relocated 1000 miles away. So nobody locally knows me from my JW days.