When does    obedience to a created being become shirk akbar?
Question

At what point does obedience to the creation in disobedience to Allah, become shirk? For example if my parents tell me to shave my beard, and I listen, am I then committing shirk? When is it considered to be shirk?
Praise be to Allah.Obedience to a created being becomes shirk in situations such as obeying that person in matters where what is forbidden is deemed to be allowed, and vice versa, or when that person issues rules and regulations, or laws, that go against the laws of Allah, and the follower believes that these laws are more complete and better than the laws of Allah, or as good as His laws, or that the laws of Allah are better but it is permissible to follow these man-made laws. The evidence for this is the aayah (interpretation of the meaning): “They (Jews and Christians) took their rabbis and their monks to be their Lords besides Allah (by obeying then in things which they made lawful or unlawful according to their own desires without being ordered by Allah)…” [al-Tawbah 9:31]. ‘Adiyy ibn Haatim said: “O Messenger of Allah, we do not worship them.”
[He was a Christian who became a Muslim - Translator]. The Messenger of Allah (peace and blessings of Allah be upon him) said: “Do they not allow you that which Allah has forbidden and forbid what Allah has allowed?” He said, “Yes.” He said, “This is a kind of worship.” The Christians’ obedience of their priests in sin and in accepting what they say about what is lawful or unlawful is a form of worshipping something other than Allah, which is a kind of shirk akbar (major shirk), that contradicts Tawheed (true monotheism).
With regard to your question, if the person who obeys his parents in sin believes that it is in fact a sin, but he does what he does because of his own desires or because he is afraid of his parents’ punishment, but it is not the matter of being forced to do so, then he is a sinner who has gone against the words of the Prophet (peace and blessings of Allah be upon him), There is no obedience to a created being if it involves disobedience of the Creator”
(reported by Ahmad, 1041; a saheeh hadeeth) – but he is not considered to be guilty of shirk akbar. But if the son believes that what his parents say overrules what Allah says about halaal and haraam, then he is guilty of shirk akbar. The Muslim has to strive against himself to bring his desires in line with what the Prophet (peace and blessings of Allah be upon him) taught, and so that he gives precedence to obeying Allah and His Messenger over obeying anyone else, and so that Allah and His Messenger are more beloved to him than anyone else. The Prophet (peace and blessings of Allah be upon him) said: “None of you truly believes until I am more beloved to him than his son, his father, and all the people.” (Reported by al-Bukhaari, 63). And Allah is the Guide to the Straight Path.