Rav Tzvi Yehuda Kook, the son of Rav Avraham Kook taught
specifically how we must love heretics. He brings the example of Avraham who
when told that Lot(very evil man) had been kidnapped during the war of the 4
kings against 5, he immediately went to war bringing his students and followers
with him just to save an evil idol worshiper. Another example he brings is
Moshe Rabbenu who came down the mountain to his followers worshiping the golden
calf. G-d told Moshe he wanted to destroy the people, but Moshe said if you
destroy them, I want you to destroy me too. He was also willing to give his
life for the sake of idol worshipers.
Rav Kook also taught that derech eretz
precedes Torah. Our sages ask: why were the armies of Ahav(one of the most evil
kings of Israel) victorious while King Saul fell in battle? Although Ahav was
wicked, there was loyalty and love between the people of his kingdom at
the time and Loshon Hara wasn't heard. In Bereahit Rabbah it is stated: so
great is peace, even if people worship idols, yet there is peace between them,
it were as if I(G-d) cannot pass judgement against them. In Saul's time, they
were the greatest scholars and tzaddikim but there was little loyalty and love,
and Loshon Hara was spoke.
