Answer them: As I live—oracle of the Lord GOD—I swear I take no pleasure in the death of the wicked, but rather that they turn from their ways and live. Turn, turn from your evil ways! Why should you die, house of Israel?
Remember that "convert" literally means "turn with".
One practice I've had in the past is saying (out loud) "I'll pray for you" with the unsaid part being "BECAUSE YOU NEED IT" (which can mean loads of things).
Obviously, I pray for people I like, because they ask me to, or because I know they need it (in various ways, and not because I'm hostile), but yes, I pray for those I dislike. Rather than pray for them to behave in particular ways or to do specific things (or to not do specific things), I usually pray for wisdom or peace or whatever it is it looks like the person needs.
Obviously, I could be the one in the wrong, and in many cases, it may be a lost cause for someone to turn their hearts or minds... but, as the New York Lottery says, ya never know. In the Gospels, and in the example of Paul, some extremely unlikely conversions occurred.
While there is breath, there is hope.