Rav Kook explains why the constructive punishment for murder was the destruction of Y'rushalayim & exile from Israel. G-d loves life and is the force behind all life, and in fact, defines "Good" as "Life". The goal of the Torah is Tahara or Life, and accordingly murder, or the taking of life is not only tragic morally but ideologically and philosophically, stands, like Tum'ah, in total contradiction to the message of life, which supersedes the other mitzvot. Israel is meant to be a life-educating "Light to the Nations" from Y'rushalayim, through building an ideal Jewish State, but if we aren't fulfilling that goal, then our capitol and national life are counter-productive.
Rav Kook deals with the classic questions asked by any thinking practicing Jew: Why did the rabbis institute so many additional rabbinic laws, which pre-occupy us day and night? Did the Torah not command us enough obligations and restrictions?! In this famous article from Orot called "Chacham Adif miNavi", Rav Kook suggests a totally innovative approach to appreciating the minutiae and ideals of Rabbinic Mitzvot, enlightening and motivating us in their observance.
A Tannaic statement emanated from the school of Rabbi Yishmael: “Should the faller fall from it (mimeneu)” (Devarim 22:8). “Mimenu” implies that the faller was fit to fall from the six days of Genesis, as the Torah calls him a “faller” before he fell. The idea is that meritorious matters are brought about by meritorious people and negative matters by negative people.
Rabbi Yishmael ben Elazar says: Due to two sins, ignorant people die: for calling the aron kodesh (ark holding Torah scrolls) arana (roughly, a closet) and for calling a beit knesset (synagogue) a beit am (house of the people).
Rabbi Yannai said: One should never put himself into a situation of danger and saying that a miracle will occur, as it is possible that the miracle will not occur, and if the miracle occurs, his merits will be lessened. This is what the pasuk [said by Yaakov] means: “I have become smaller due to all the kindness and the truth that You have done for Your servant” (Bereishit 32:11)
Rav would not pass in a ferry in which a non-Jew was sitting, as he would say: “Perhaps there is a decree upon him, and I may be affected along with him.” Shmuel would pass only in a ferry in which a non-Jew was sitting, as he would say: “Anger against the members of two nations will not have dominion.” Rabbi Yannai would check [for holes in the ferry – Rashi]. Rabbi Yannai was consistent in his approach, as he would say: “A person should never stand in a place of danger and assume that a miracle will happen to him, for not always is a miracle done for him, and if a miracle does occur, it is subtracted from his merits.”
[The gemara is based on p’sukim in Tehillim (73:4; 49:13), which are very hard to translate, especially if one wants to translate them according to p’shat and also wants to understand them in context of Chazal’s derasha. Therefore, we will bring the statements without the p’sukim upon which they are based.] Hashem said: It is not enough that the wicked are not afraid and saddened about the prospect of the day of their death, but their heart is as robust as the opening of a hall. This is as Rabba said: The wicked know that they are headed to death, but they have fat over their kidneys [to keep them from reacting appropriately]. This is despite the fact that they have not forgotten their destiny.
Ulla expounded: That which it says, “Do not be evil very much …” (Kohelet 7:17), doesn’t that imply that it is only very much that one should not be evil, but he may be evil a little bit. Rather, [it is related to the idea] that one who ate garlic and his breath smells, should he once again eat garlic and have his breath smell [worse]?