A Time for Teshuvah
חנוכה comes from the word חינוך, which signifies that חנוכה is a time for teshuvah, a time when we are מחנך ourselves to improve our ways.
Al HaNissim discusses the miracles Hashem performed for us in the war against the Yevanim. We say, ורבים חלשים ביד גבורים מסרת מעטים ביד, "You delivered the mighty into the hands of the weak, the many into the hands of few." Until here it is understood. It was a great miracle that the few and the weak won against the many and the mighty. However, after this we say in the Al HaNissim, וטמאים תורתך עוסקי ביד וזדים ,צדיקים ביד ורשעים ,טהורים ביד, that Hashem delivered "tame'im into the hands of the tehorim, resha'im into the hands of tzaddikim, sinners into the hands of those who study Torah." Why is it miraculous that sinners and resha'im were given over into the hands of the righteous and those who studied Torah?
Sefarim write in the name of the Bardichover Rav zy'a, that the final words refer to the wave of teshuvah that happened at that time. טהורים ביד טמאים, the impure people did teshuvah and became pure. רשעים צדיקים ביד, the resha'im changed their ways and became tzaddikim. תורתיך עוסקי ביד וזדים, sinners began to study Torah. When they saw the miracles that Hashem did, there was a great movement of teshuvah that followed.
The resha'im at that time were called the מתיונים. They were Yidden who wanted to be like the Greeks. When they witnessed the miracles, they did teshuvah and returned to their heritage.