If you are "born" into the truth, it's the only thing you've known. If that is the case with your friends, then offering a different glimpse of the world - not the dark and gloomy gray glasses of the WT doctrines - can sometimes help. Positive experiences that go against what the WT likes to pound into the heads of the followers.
I can tell when the witness at work, is thinking of how to say "the world is getting worse and worse" That is what all witnesses are trained to do when "witnessing" The last time she told me that, I said "Well then, go back and live in Roman times" That ended her little speech. Would she like to live in that time period? No. It brings to mind the unknown diseases, wars, and slavery. A few days after me saying that, I heard her trying it out on someone in the office. He counteracted by saying he believed there is far more good in the world than bad. He refused to give into her "the world is terrible and it will only get worse" line. She finally gave up. Will it change her mind? Only if she is willing. The old adage "you can lead a horse to water but you can't make it drink" applies.
And that is what may happen with your friends. If they are happy with what the religion gives them, or they are afraid of losing their place in paradise, all your efforts will fail. But it doesn't hurt to try.
Good friends love their friends unconditionally and respect boundaries and their decisions, and love them anyway. Just sayin'.
Good friends also warn them about dangerous situations and con men. Because they love them.