The ten spies (excluding Yehoshua and Kalev), who came back from their mission with fear, also imbued the nation with great fear. When describing the giants and their cities surrounded by huge walls, the spies expressed feeling like midgets or even like grasshoppers (see Bamidbar 13:28-33). Kalev ben Yefuneh, who was not intimidated by them because of his belief in Hashem, merited conquering Chevron, home to some of the most prominent giants, and receiving it as his estate (see Yehoshua 14:12-15; ibid. 15 13-14).
The giants are mentioned already in Sefer Bereishit (14:5). The context there is the battles of the enemies of Avraham, the four kings who were led by Amrafel, who Chazal identify as Nimrod, the tyrannical king who threw Avraham into a furnace. When Avraham emerged safe and victorious after defeating these kings and liberating his captive nephew Lot, there was a victory celebration in Emek Hamelech, which was attended by Malki-Tzedek, the King of Shalem (Yerushalayim).
The next generation to fight the giants of the region was that of David, the descendant of Ruth the Moavite, a descendant of Lot. David and his friends killed Goliat and "children of Rafah," who is identified as Orpah, sister-in-law of Ruth (see Shmuel II: 21:16-22 and Sota 42b). In a talk I have presented on Yom Yerushalayim, I mentioned that after David’s killing of Goliat, he brought the latter’s decapitated head to Yerushalayim.
At that point, a circle that had been begun at the time of Avraham was completed. Avraham was the first to see a special cloud over Mt.Moriah, signifying its sanctity and importance to him and future generations. The Divine Presence that dwelled at that place spread out over the entire Land of Canaan, turning it into the Land of Israel. Avraham, who was the father of the believers of his time, received theLand of Israel for the nation that he began in the merit of this belief. He knew that there were intimidating giants throughout the Land. Hashem sent Nimrod, of all people, a non-believer in Hashem, to defeat the giants. This actually made it easier for Avraham’s descendants to acquire the Land. Kalev was another believer among those weak in belief, and he continued the job of killing giants who tried to stop Bnei Yisrael from acquiring the Land. David was chosen by Divine Providence to continue the job by killing Goliat and bringing his head to Yerushalayim. In that way, David proved that he was continuing the tradition of fighting the giants. He was the father of a Kingdom of Israelthat was based on justice and charity in the Land given to Avraham and the sons of his grandson, Yaakov.
The battle for control of Eretz Yisrael is a long and exhausting one. Only one who is armed with a great amount of belief will merit seeing a State of Israel that is built in full glory and founded on justice and charity. Shortcuts and magical solutions largely contradict the approaches of Avraham and David.