Not that I necessarily engage with the sole purpose of trying to convince them with words or arguments, even though I absolutely will provide scripture if they are receptive. But in general I heavily suck in that department - words, debates, arguments. But I don't think of them as lost causes. If I did, I should think of myself as one too. I've done and said some awful things. I should remember myself, and also Paul, who violently persecuted the body of Christ. What I can do is to humble myself, treat them with love without wanting anything back, and pray for them, for God to work in them and through me in any ways He sees fit. My abilities only go so far, my patience, humility and judgement can be quite shaky, so I go to Christ with my concerns about my neighbor. Concerning the people I deal with, that is. I don't go out seeking for strangers as I am a hermit and a weirdo.