I would like to discuss in greater detail Chabad and its alleged deviance from acceptable theology. What seems to be happening is that Chabad follows views which at one time were common or viewed as legitimate. Over time some of these views fell out of favor of the yeshiva world. The Holocaust is one such issue. The following quotes are from R Telushkin's book on the Lubavitcher Rebbe.
One simple way of resolving the apparent contradiction between the approach of the Lubavitcher Rebbe and Rav Shach is based on the following sources. Causal relationships are attriubted for pragmatic reasons - but not actually known. Typically throughout Jewish history it has been beneficial to faith to attribute suffering to sin. However except in the case of the prophets, the actual causal relationships are not known. Such attributions not only provide a way of understanding suffering but it also provides motivation to improve and grow from the suffering.
However what would happen in a situation where these attributions not only are not viewed as providing meaning but are viewed as abhorrent? What if the reaction to these explanation is anger and rebellion against a religion that insists that G-d brings about the torture and death of millions of men, women and children? And even in those who don't reject the view, it induces severe depression rather than growth and meaning? This is common in the modern world - even amongst many religious people.
The answer is obviously that we should you a different approach. Such is the approach of Chabad - which obviously doesn't reject the idea of Divine Providence - but says we don't understand the causal relationships. This can be seen in the following quote. More citations are at the end of this post. [These translated sources are from my sefer Daas Torah.]
Kuzari (5:20): Since all that exists must exist either because of a direct decree of G d or by means of intermediate factors and it is possible that they are all directly decreed by G d - the masses prefer to attribute all causes directly to G d because this is more certain and strengthens faith.
18 . Rabbi Shach’s statement was cited on December 29, 1990, in Yated Ne’eman, a newspaper that he cofounded . A fuller transcript of his remarks can be found in Mussar Eruai Ha-Tekufah (Bnai Brak, Israel: 2011), 35– 38.
Telushkin, Joseph (2014-06-10). Rebbe: The Life and Teachings of Menachem M. Schneerson, the Most Influential Rabbi in Modern History (Kindle Locations 2664-2671). HarperCollins. Kindle Edition.
In characteristic fashion, the Rebbe never responded to Rabbi Shach by name, though he did offer a full speech in repudiation of his comment that the Jews who were murdered in the Holocaust were being punished for both their and their ancestors’ sins. In the Rebbe’s words, “as regards the awful events of the last generation [i.e., the Holocaust], it is clear and obvious (barur ve-pashut) that they did not come as punishment.” 22 He returned to this issue again: “To say that those very people were deserving of what transpired, that it was a punishment for their sins, heaven forbid, is unthinkable. There is absolutely no explanation or understanding for the Holocaust. . . . Certainly not the explanation of a judgment and punishment. No scales of judgment could ever condemn a people to such horrors.” Instead of speaking of the supposed sins of the six million (and their ancestors), the Rebbe spoke of each of the Holocaust victims as martyrs who had died al kiddush Hashem, “in sanctification of God’s Name.” 23 Why , then, did God permit the Holocaust? As the Rebbe once answered a correspondent who challenged him with this question: “The only answer we can give is ‘Only God knows.’ ” 24 Furthermore, the Rebbe emphasized that evil sometimes reflects rather the ability of evil human beings to misuse their free will. Commenting on the promise offered in Deuteronomy 32: 43, “For He [God] will avenge the blood of his servants,” the Rebbe noted that the very wording of the Torah verse suggests that the death of these “servants” is against God’s will; that is why He will avenge it. In a comment that serves as a response to the view that God was counting the Jewish people’s sins, the Rebbe said, “God forbid that one should picture God as a cruel king who punishes His people for their disobedience and then waits until it mounts again to the point at which it is fitting to punish them again.” 25 Rather, in the Rebbe’s view, God should be depicted not as “the Master of punishment” but as “the Master of mercy.” 26
Telushkin, Joseph (2014-06-10). Rebbe: The Life and Teachings of Menachem M. Schneerson, the Most Influential Rabbi in Modern History (Kindle Locations 2709-2728). HarperCollins. Kindle Edition.
Rav Shach's words - from מוסר אירועי התקופה found at Hebrew Books
Rambam (Moreh Nevuchim 2:48): It is very clear that everything that happens must have something that caused it. That cause must itself have a cause. This chain continues until we arrive at the original cause - namely G d’s will and desire. Because ultimately everything is caused by G d, the prophets sometime attribute things caused by intermediate factors as being caused by G d. All of this is well known and this is in fact the view of the men of Torah…. You should know that all proximate causes which produce that which is produced - with no distinction made between whether the intermediately causes are essential, natural, free will (of man or animal) or accident - they are all attributed by the prophets to G d. For example natural events such as the snow melting from the warm air or waves created by the wind are described by the prophets as being commanded by G d as is the falling of the rain… Concerning that which is caused by man’s free will such as war between two nations or one person attempting to harm or even insult another person - the prophets describe it as the result of G d’s command. … When Yosef was freed from prison the prophet said that G d sent a king and freed him. Furthermore Yosef said to his brothers that they had not sent him to Egypt but rather G d had. We also find that events caused by the desires of animals are described as being caused by G d such as “G d spoke to the fish” (Yonah 2:11) since G d in fact initiate the desire of the animal. Even things which are accidental from pure chance are attributed to G d. For example concerning Rivkah, “Let her be your master’s son’s wife as G d has spoken (Bereishis 24:51). And Yosef said that “G d sent me before you” (Bereishis 45:7).
Chovas HaLevavos (3:8): I have found in books information about Divine compulsion, decree, rulership, and will. They state that everything is controlled by G d from mineral, plant and animal to human beings. Tehilim (135:6): G d does whatever He wants to do in Heaven and earth…. There are many similar verses that teach this idea that man and other creatures were prepared merely to adorn the world. That they move only with His permission, with His power, and with His ability. … Our sages had intense debates about how to reconcile Divine compulsion and Divine justice… Some held man has total free will and that is why man receives reward and punishment. Others held the opposite that everything is determined by G d… When this latter group is asked about reward and punishment they respond that it is a mystery but G d is just in whatever He does… There is a third group which believes in both Divine compulsion and Divine justice. But they add that whoever delves into the matter cannot avoid sin and trouble no matter how he attempts to explain the matter. They claim that the best approach is to have full faith that man has full free will and will be rewarded and punished for his deeds… but at the same time to have the full trust in G d as one who believes that everything is fully determined by G d. Furthermore to believe that G d can make claims against man but man cannot demand anything of G d. This position is closer to resolving the problem than the others. That is because our ignorance of G d’s wisdom is well known because of the weakness of our minds and the limited awareness. But in fact our ignorance is the means by which G d shows His kindness to us and that is why it is hidden from us. Because if there was any benefit in revealing this secret then G d would have revealed it to us.
Kuzari (5:20): … The Prime Will is manifest when the Divine Presence is amongst the Jews. However after the destruction of the Temple it became doubtful - except in the hearts of those who have faith - whether specific events were the result of the direct command of G d or the Heavenly spheres or were accidents. There is no definitive way to resolve this issue. Nonetheless it is best to attribute everything that happens to G d, especially major things such as death, victory, war, success and bad fortune.
Rabbeinu Bachye (Kad HaKemach Bitachon): An aspect of bitachon in G d is that even when a person has wealth, possessions, peace of mind and honor - he should not assume that this is reward for his good deeds. Even if he is a complete tzadik, it is better to even consider himself wicked and ascribe all the good entirely to the kindness of G d. On the other hand, if he suffers calamities or is attacked by bandits he should not view it as simply bad luck…. Such a response is the path of heresy. Rather he should ascribe the suffering to his many sins. In fact, if he insists that his suffering is merely bad luck, G d will give him additional “bad luck”…
Rambam (Taanis 1:3): But if a person doesn’t call out to Heaven and doesn’t blow shofar but simply says that the misfortune is entirely a natural event and the calamity simply happened, that is the way of cruelty and causes them to adhere to their evil deeds and to have even more suffering. As the Torah (Vayikra 26:24) says “If you relate to Me as life was full of accidental events than I will treat you as if everything is an accident.” In other words G d will bring on you additional suffering so that you will repent if you say that the suffering is just accidental.