What is the importance of Muhammad (Sallallahu Alaihi wa Sallam) to Muslims?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions. Allah Created mankind for a clear purpose. The purpose is to worship Him alone. He Says in His Glorious Book, {I have not Created Jinn and man but in order that they should worship Me}. It is in order to achieve this goal that the Messengers were sent to mankind as bringers of glad tidings and warners. They called people to the way of Allah and explained to them the ways that lead them to Allah. The last of these Messengers is Muhammad (Sallallahu Alaihi wa Sallam) to whom Allah revealed the best of His Books. Allah Says (interpretation of meaning): {And We have sent down to you (O Muhammad SAW) the Book (this Qur'ân) in truth, confirming the Scripture that came before it and Mohaymin (trustworthy in highness and a witness) over it (old Scriptures).}[5:48]. We Muslims have no doubt that there is no way to happiness and success in this world and the Hereafter except through the Messenger of Allah (Sallallahu Alaihi wa Sallam). There is no way to know the good and the bad in details except through him. This is because, he is the conveyor of the religion from Allah. Allah Says (interpretation of meaning) addressing His Messenger: {Your duty is to convey the message}[42:48]. Allah also Says (interpretation of meaning): {And we have also sent down unto you (Muhammad)…..}[16:44]. He also Says, {Indeed in the Messenger of Allah (Muhammad) you have a good example to follow for him who hopes for (the Meeting with) Allah and the Last Day, and remembers Allah much}[33:21]. The good deeds, words and traits are found only in his guidance. His guidance is the strongest criterion for all saying, deeds and traits. It is through following him that people of guidance are distinguished from erroneous people. Allah Says (interpretation of meaning): {But no, by your Lord, they can have no Faith, until they make you (O Muhammad) judge in all disputes between them, and find in themselves no resistance against your decisions, and accept (them) with full submission}[4:65]. Ibn Katheer said, while commenting on the above verse, Allah Swears by His Noble and Holy Self that no one believes until he accepts the decision of the Messenger of Allah (Sallallahu Alaihi wa Sallam) on all matters. Whatever the Prophet (Sallallahu Alaihi wa Sallam) decides is the truth that should adhered to inwardly and outwardly. Allah also Says (interpretation of meaning): {It is not for a believer, man or woman, when Allah and His Messenger have decreed a matter that they should have any option in their decision.}[33:36]. The true believer does not prefer his wishes or inclinations to what Allah and His Messenger decide. This is why Allah Commands in more than 30 places in the Qur'an that His Messenger should be obeyed, according to Ibn Taymiyah . There are many proofs that indicate that obedience to the Messenger of Allah is obligatory. Some of them are: 1. {Say (O Muhammad): "Obey Allah and the Messenger (Muhammad)". But if they turn away, then Allah does not like the disbelievers.}[3:32]. 2. {O you who believe! Obey Allah and His Messenger, and turn not away from him (i.e. Messenger Muhammad) while you are hearing.} [8:20]. 3. {And obey Allâh and the Messenger (Muhammad SAW),…} [5:92]. These above verses and others contain Allah's Command that His Prophet (Sallallahu Alaihi wa Sallam) be obeyed. There are also many verses that explain the reward of those who obey the Prophet (Sallallahu Alaihi wa Sallam). Examples of these are Allah's Sayings, {If you obey him, you shall be on the right guidance.} [24:54]. {And whosoever obeys Allah and His Messenger, he has indeed achieved a great achievement.}[33:71]. {And whosoever obeys Allah and His Messenger, He will admit him to Gardens beneath which rivers flow.}[48:17]. These verses explain that attainment of guidance, success and enjoyment in the blissful Paradise depend on one's obedience to the Messenger (Sallallahu Alaihi wa Sallam). Just as the Glorious Qur'an encourages that the Prophet (Sallallahu Alaihi wa Sallam) be obeyed, the Prophet (Sallallahu Alaihi wa Sallam) himself encouraged his Ummah to obey and emulate him. There are many Ahadith to this effect. Some of these are: The Messenger of Allah (Sallallahu Alaihi wa Sallam) said, All my Ummah will enter Paradise except him who refuses to. The companions said, Who will refuse to O, Messenger of Allah? He said, Whoever obeys him will enter Paradise and whoever disobeys me has refused to enter Paradise [Reported by Imam Al-Bukhari ]. He also said, Whoever obeys me has obeyed Allah and whoever disobeys me has disobeyed Allah. [Reported by Al-Bukhari ]. These above Ahadith indicate that the only way to the obedience of Allah and to Paradise is to obey the Messenger. As Allah explains the necessity of obeying His Prophet (Sallallahu Alaihi wa Sallam), and the reward of him who obeys him, He also warns against disobeying him. He Says in the Glorious Qur'an, {And whoever disobeys Allah and His Messenger, he has indeed strayed into a plain error.}[33:36]. He also Says, {…And let those who oppose the Messenger's (Muhammad SAW) commandment (i.e. his Sunnah legal ways, orders, acts of worship, statements, etc.) (among the sects) beware, lest some Fitnah (disbelief, trials, afflictions, earthquakes, killing, overpowered by a tyrant, etc.) befall them or a painful torment be inflicted on them.}[24:63]. Allah also threatens those who disobey the Prophet's (Sallallahu Alaihi wa Sallam) orders with Fire and severe punishment. He Says, {And whoever defies and disobeys Allah and His Messenger, then verily, Allah is Severe in punishment.}[8:13]. He also Says, {And whosoever disobeys Allah and His Messenger, then verily for him is the Fire of Hell.}[72:23]. Anybody who defies and disobeys the Messenger of Allah has gone astray and it is likely that he will be afflicted with Fitnah. The Fitnah as interpreted by Imam Malik means, disbelief (Kufr). He is in addition to this, threatened with disgrace and ignominy in this world. The Messenger of Allah (Sallallahu Alaihi wa Sallam) said, Ignominy and humiliation are made the lot of him who disobeys my order [Reported by Ahmad ]. We seek refuge with Allah from disobeying His Prophet (Sallallahu Alaihi wa Sallam). We also beseech Him to guide to obeying him. Allah knows best.