Is it correct to say that the Muslims are acting in the Prophet’s stead in calling people to Islam and spreading the message of Islam?
Question

Is it permissible to say that the Muslims are acting in the stead of the Prophet (blessings and peace of Allah be upon him) and of the Companions in carrying the message of Islam and conveying it?
Praise be to Allah.Yes, it is correct to say this. The Muslims are acting in the Prophet’s stead in conveying the message of Islam, calling people to it and explaining the teachings of Islam and conveying them to people.
The most deserving of the Muslims to be described as acting in the Prophet’s stead are the scholars.
This was stated by some of the scholars, such as ash-Shatibi (may Allah have mercy on him), who said:
The mufti is acting in the Prophet’s stead in the Muslim community.
The evidence for that is found in several things:
-1- The religious texts. In the hadith it says that the scholars are the heirs of the prophets. The prophets did not leave behind any dinars or dirhams (that is, wealth); rather they left behind knowledge. In as-Sahih it is narrated that the Prophet (blessings and peace of Allah be upon him) said: “Whilst I was sleeping, I saw a vessel that was brought to me, in which was milk. I drank from it until its moisture flowed from beneath my nails, then I gave my leftovers to ‘Umar ibn al-Khattab.” They said: How did you interpret that, O Messenger of Allah? He said: “Knowledge.”
The Prophet (blessings and peace of Allah be upon him) was sent as a warner, as Allah, may He be exalted, says (interpretation of the meaning): “But you are only a warner” [Hud 11:12], and He says of the scholars (interpretation of the meaning): “For there should separate from every division of them a group [remaining] to obtain understanding in the religion and warn [i.e., advise] their people ” [at-Tawbah 9:122].
-2- The scholar is acting in the Prophet’s stead in conveying the rulings of Islam, because the Prophet (blessings and peace of Allah be upon him) said: “Let those of you who are present convey to those who are absent.” And he (blessings and peace of Allah be upon him) said: “Convey from me, even if it is one verse.” As that is the case, it means that he is acting in the Prophet’s stead.
-3- The mufti is a lawgiver in one sense, because what he conveys of Islamic rulings is either transmitted from the Prophet (blessings and peace of Allah be upon him) or it is derived from the religious texts that were narrated from him. In the former case, he is conveying it and in the latter case he is acting in his stead by initiating rulings, and initiating rulings is only for the lawgiver. If the mujtahid (mufti) initiates rulings based on what he thinks and works out, then in this sense he is a lawgiver and must be followed. This definitely means that the scholar is the successor of the Prophet (blessings and peace of Allah be upon him), and even in the case where he is only conveying the ruling that was given by the Prophet (blessings and peace of Allah be upon him), he still has to examine the matter and understand the wording of the text, and understand the reasons for the ruling and how the ruling is connected to its reason. In both cases, he is the one who must do that, so in this regard he is acting in the lawgiver’s stead in that sense. It says in the hadith: “Whoever reads the Qur’an, prophethood is placed in his heart.”
In conclusion, the mufti is telling people the rulings of Allah, as the Prophet (blessings and peace of Allah be upon him) did; and is approving or disapproving of the deeds of accountable people on the basis of his understanding, as the Prophet (blessings and peace of Allah be upon him) did; and his rulings are to be implemented by the Muslims, because he is the successor to the Prophet (blessings and peace of Allah be upon him). Hence the scholars are called those in authority, and obedience to them is mentioned alongside obedience to Allah and His Messenger in the verse (interpretation of the meaning): “obey Allah and obey the Messenger and those in authority among you” [an-Nisa’ 4:59].
There is a great deal of evidence to support this concept. End quote.
Al-Muwafaqat (4/201).
And Allah knows best.