It states (Koheles 10:8) נָחָש יִשְּׁכ ֶנּוּ גָּדֵר וּפֹרֵץ, "He who breaks down a gate will be bitten by a snake." The Chofetz Chaim (Shem Olam ch.6 footnote) asks why it states נָחָש יִשְּׁכ ֶנּוּ, and not that he will be bitten by a lion, which is a greater pain? The explanation is that when one is bitten by a lion, he knows immediately that he is in danger, and he immediately seeks medical help. However, when one is bitten by a snake, he doesn't realize at first just how serious it is. The poison gradually passes through his blood, and only then does he feel and realize the great danger he is in.
The same applies to one who transgresses one of the gedarim, safeguards, established by the gedolei Yisrael. At first, he doesn't realize that something terrible occurred. But later he will discover how much he fell, all because he thought he was smarter than the chachamim, and he thought that it wouldn't harm him.
Year (1986) ו"תשמ, there was a nuclear disaster in the city of Chernobyl, Ukraine (which was then part of the USSR). Since then, Chernobyl has been a destroyed city, and it is dangerous to live there. Some foolish people thought that they were wise, and they went to Chernobyl and spent time there. They said that nothing would happen to them, and the warnings of the government are unreal and untrue. When they left, and they were well, they announced, "Look at us. Nothing happened. It's just a conspiracy." They didn't know that the radiation went into their bodies, and gradually they became ill. Even their children, who were born years later, were ill.
The same can be said about those people who claim to be wise, and they say nothing will happen to them if they are lax with the takanos of the chachamim of our generation. They proclaim with a loud voice, "You see, I have internet and nothing happened to me." But they don't know that, although they think they are well, they are harming themselves and their children. They think it is nothing, that it is a joke, but they are damaging themselves.
The Gemara (Menachos 43b) states, "Whoever wears tefillin on his head and arm, tzitzis on his clothes, and a mezuzah on his doorpost, won't be quick to sin." These mitzvos will protect him from performing aveiros. Rashi writes, יחטא שלא בחזקה עומד, we can assume that he won't sin. This is as it states (Koheles 4:12) יִנָּתֵק בִמְהֵרָה לֹא ׁׁ ֻלָּשהַמְש וְה ַחוּט, "a three-ply cord is not easily severed!" And it states (Tehillim 34:8) וַיְח ַלְּצֵם לִירֵא ָיו סָבִיב 'ה מ ַלְאַ ךְ חֹנֶה, "The angel of Hashem encamps around those who fear Him, and He saves them." Rashi writes that Hashem saves them from aveiros.
The Maharsha explains that each mitzvah creates a malach, and these three mitzvos, tefillin, tzitzis, and mezuzah, create malachim that סביב חונה, encamp around him and protect him from performing aveiros.
The Shevet HaLevi (Reb Shmuel Wosner zt'l, parashas Shlach, ע"תש) asks, "Who from Bnei Yisrael isn't cautious to keep these mitzvos [talis, tefillin, and mezuzah] carefully, and l'mahadrin? So, why aren't they protected from aveiros? Chazal guaranteed us that we will be protected from performing aveiros when we keep these three mitzvos!
Shevet HaLevi explains that although people are cautious with these mitzvos, they also bring into their homes the tamei and 'cursed devices. So, how will it help them if they have a mezuzah on their doorpost, outside the home, when inside the home there is a tamei device? About this, we can use the words written in the piyut of Yom Kippur before kedushah of Shacharis, לבית אוי מתוכו מחריביו אשר, "Woe to the house that the destructors are within it."
Reb Wosner added that the same is with the tzitzis and the tefillin, which protect from aveiros. However, in his pockets, he carries a non-kosher telephone, connected to all types of tumah, from which one is in danger of falling to the lowest places, with no return. The most precious and mehudar tefillin won't protect him, and the most kosher tzitzis won't help him, because there is a tumah within him!
