When the forth Gerrer Rebbe, the Beis Yisroel, lived in Haifa, his chassidim would gather under the balcony to his house every seudas shlishis (third meal on shabbos), and the Rebbe would give over his most inspirational words of Torah for the week. On one particular shabbos, after the chassidim had congregated under the balcony, the Rebbe was nowhere to be seen. His chassidim looked around until someone spotted the Rebbe at the corner, bent over, talking to someone in a car at a red light. Word spread among the group, and no one could believe the site. There was the Rebbe talking to someone in a car on shabbos! A few chassidim rushed over, and overheard the following being said by the Rebbe in a voice of great enthusiasm: "Yes, it's yours too! It doesn't only belong to me, it belongs to you, as well! Shabbos is for every Jew. It doesn't matter that I dress one way and that you dress another. Each one of us is a tzelem Elokim (created in the image of G-d). Perhaps you've never been privileged to experience the joys of shabbos, so now it is time!" With that the Rebbe invited the man in the car over for the following shabbos. He pointed to the house, and told him that he would be in for otherworldly pleasures if he were to come. The man became a frequent guest of the Rebbe and, in time, became shomer shabbos.
In a similar story a number of years ago there was a young rebel who decided to go speeding through the streets of Mea Shearim on a shabbos afternoon with his radio at full volume. As you could imagine, the indignant shouts of "shabbos, shabbos!" could be heard block in and block out. The indentations on the car from the stones hurled by angry chassidim had already become evident after a few blocks. But at the end of a long street, up which this driver was heading, stood a chosid. Bedecked in shtreimel, bekishe, and full shabbos regalia, he stood firmly and resolutely in the middle of the street with his hand straight out. The driver had no choice but to stop. The chosid let down his arm, and walked to the driver's side of the car. "How would you like to come to my house for a shabbos meal?" he asked warmly with a bright smile on his face. "How would I like to what???" asked the driver." The chosid repeated, "how would you like to come to my house for a shabbos meal? I would love to have you at my house for a shabbos meal." The driver was dumbfounded. What happened to all of the yelling? What happened to all of the hateful stares? After all, that was the purpose of his drive through the neighborhood on shabbos. He literally didn't know how to react. The chosid continued, "perhaps you've never celebrated a shabbos in full form. I want to show you what it's like. I would really love to have you over next week." After a few more minutes of convincing, the driver really didn't know what else to do, but accept. He took the address, managed to find a yarmulke the next week, and actually made it to the chosid's house for shabbos. The rebel had no idea that one day he would become shomer shabbos.
If some of these kana'im would just do something positive; invite someone less religious over for a shabbos meal, or learn with someone secular once a week. There are so, so many possibilities for improving the world.
40 years in the midbar (desert), and the Torah records only one act of zealotry, Pinchas. This was the exalted generation that experienced the highest levels of prophesy at kriyas yam suf (the splitting of the Sea of Reeds). This was the generation that received the Torah at har sinai, and heard the voice of G-d. And only one act of zealotry. So for people who belong to a generation that has sunken so low to pick up bottles and pick up rocks, and set fires and do worse... This clearly isn't in the spirit of living a Jewish life.
