"How should I behave when confronted by the seemingly ubiquitous gentile
preachers and proselytizers? Are the admonitions such as [Deut. 13:4]
"You should not listen to the words of that prophet," absolute.
Of course, no purpose is served by
arguing or debating with them; that's precisely what they're trying to
provoke. But must I immediately change the television channel if I see
a preacher, or quickly walk by if one of those obnoxious street evangelists
is in my path? Or is it permissible to listen to them and watch their
histrionics for entertainment?...to learn what is on the minds of our
non-Jewish neighbors?...to be prepared for the inquiries of confused and
Don't give them so much credit! The "prophet" of Deut. 13 is
someone who claims that G-d spoke directly to him and told him to spread
this particular word. If he proselytizes based on what G-d "told"
someone else, or on his own understanding of scripture, he already cannot
be classified as "false prophet."
If he actually claims that "G-d" ordered him to tell Jews to
go against the Torah, you should certainly turn aside quickly. But even
if he doesn't you should probably walk away! To listen to them for curiosity
or entertainment is to have "your gain swallowed up by your loss"
[Avot 5:11]. These sorts of inanities and impurities have a tendency to
linger in the mind. You don't need it.
Interacting with them in order "to be prepared for the inquiries
of confused and uneducated Jews" might be reasonable if you have
Jews asking you such questions. To do it because maybe you will be asked
one day can only be called kidding yourself.