First, it should be noted that to call oneself an Ahmadi, it is indeed sufficient to accept the Promised Messiah(as). The Khulafa of the Promised Messiah(as) and those who have pledged allegiance to them have never denied that those who do not accept the Khulafa and do not pledge allegiance to them are Ahmadis.
However, the election of and pledge of allegiance to a Khalifa is obligatory, it is a divinely imposed duty like any other. The proof of the obligation to elect a Khalifa and pledge allegiance to him is derived from both the sunnah of the Messenger(sa) and the consensus (ijma) of the Companions(ra).
The Necessity of Establishing Khilafat and Pledging Allegiance to It
As far as the sunnah is concerned, there is for example the following tradition. The Messenger(sa) of Allah said:
مَنْ خَلَعَ يَدًا مِنْ طَاعَةٍ لَقِيَ اللّٰهَ يَوْمَ الْقِيَامَةِ لاَ حُجَّةَ لَهُ وَمَنْ مَاتَ وَلَيْسَ فِي عُنُقِهِ بَيْعَةٌ مَاتَ مِيتَةً جَاهِلِيَّةً
“He who forsakes obedience will find no argument when he stands before Allah on the Day of Resurrection, and he who dies without having pledged allegiance dies a death of Jahiliyya [non-acceptance of Islam].” (Sahih Muslim, The book on government, hadith 1851a)
The Holy Prophet(sa) also said to Hazrat Huzayfa(ra) ibn al-Yaman about the Latter-Days, and the latter reports:
دُعَاةٌ إِلَى أَبْوَابِ جَهَنَّمَ، مَنْ أَجَابَهُمْ إِلَيْهَا قَذَفُوهُ فِيهَا قُلْتُ يَا رَسُولَ اللّٰهِ صِفْهُمْ لَنَا فَقَالَ”هُمْ مِنْ جِلْدَتِنَا، وَيَتَكَلَّمُونَ بِأَلْسِنَتِنَاقُلْتُ فَمَا تَأْمُرُنِي إِنْ أَدْرَكَنِي ذَلِكَ قَالَ “تَلْزَمُ جَمَاعَةَ الْمُسْلِمِينَ وَإِمَامَهُمْ قُلْتُ فَإِنْ لَمْ يَكُنْ لَهُمْ جَمَاعَةٌ وَلاَ إِمَامٌ قَالَ فَاعْتَزِلْ تِلْكَ الْفِرَقَ كُلَّهَا، وَلَوْ أَنْ تَعَضَّ بِأَصْلِ شَجَرَةٍ حَتَّى يُدْرِكَكَ الْمَوْتُ وَأَنْتَ عَلَى ذَلِكَ
“‘There will be some people who will invite others to the gates of Hell, and whoever accepts their invitation to it will be thrown in it.’ I said, ‘O Allah’s Messenger(sa)! Describe those people to us.’ He said, ‘They will belong to us and speak our language.’ I asked, ‘What do you order me to do if such a thing should take place in my life?’ He said, ‘Adhere to the community of Muslims and their Imam.’ I asked, ‘What if there is neither a community nor an Imam?’ He said, ‘Keep away from all those different sects, even if you had to eat the root of a tree, till you meet Allah while you are still in that state.’” (Sahih al-Bukhari, Kitab al-Fitan, hadith 7084)
The Messenger(sa) has thus made the pledge of allegiance obligatory on every Muslim. He describes the one who dies without having taken a pledge of allegiance as one who dies the death of a non-believer (jahiliyyah). The Messenger(sa) of Allah has thus made incumbent on every Muslim the pledge of allegiance; the obligation is therefore for every Muslim to take this pledge of allegiance.
This essentially presupposes the existence of an Imam and Khalifa, who by his very existence has the right to have Muslims pledge allegiance to him. In turn, it is the existence of the Khalifa that necessitates the pledge of allegiance to him by every Muslim. Therefore, this hadith is proof that the election of a Khalifa is obligatory and that every Muslim is obliged to pledge allegiance to that Khalifa. The Messenger(sa) of Allah admonished the absence of a Muslim’s pledge of allegiance until his death.
Then the Messenger(sa) of Allah also said to the believers:
تَكُونُ خُلَفَاءُ فَيَكْثُرُوا قَالُوا فَكَيْفَ نَصْنَعُ قَالَ أَوْفُوا بِبَيْعَةِ الأَوَّلِ فَالأَوَّلِ أَدُّوا الَّذِي عَلَيْكُمْ فَسَيَسْأَلُهُمُ اللَّهُ عَزَّ وَجَلَّ عَنِ الَّذِي عَلَيْهِمْ
“There will be Khulafa and there will be many of them.” They asked, ‘What should we do?’ He said, ‘Fulfil your pledge of allegiance to the first one, then the one who comes after him, and do the duties required of you, for Allah will question them about the duties upon them.’” (Sunan Ibn Majah, Kitab al-Jihad, hadith 2871)
Referring to a recurring pattern of divine communities and their authorities, the Messenger(sa) of Allah said:
ما كانَتْ نُبُوَّةٌ قَطُّ إلّا تَبِعَتْها خِلافَةٌ، ولا كانَتْ خِلافَةٌ قَطُّ إلّا تَبِعَها مُلْكٌ
“There has never been a prophethood except that it was followed by Khilafat, and there has never been a Khilafat except that it was followed by a kingship.” (Mashyakhah Ibn Tahman, hadith 40)
Since the Promised Messiah(as) was a non-legislative shadow-prophet of the Holy Prophet of Islam (who had confirmed this prophetic status), on a purely logical basis, this pattern had to apply to him as well and a rightly-guided Khilafat was to follow him.
Khilafat Will Be Established After the Mahdi
In another tradition, the Messenger(sa) of Allah prophesied:
تَكُونُ النُّبُوَّةُ فِيكُمْ ما شاءَ اللّٰهُ أنْ تَكُونَ، ثُمَّ يَرْفَعُها إذا شَاءَ أنْ يَرْفَعَها، ثُمَّ تَكُونُ خِلافَةٌ عَلى مِنهاجِ النُّبُوَّةِ، فَتَكُونُ ما شاءَ اللّٰهُ أنْ تَكُونَ، ثُمَّ يَرْفَعُها إذا شاءَ اللّٰهُ أنْ يَرْفَعَها، ثُمَّ تَكُونُ مُلْكًا عاضًّا، فَيَكُونُ ما شاءَ اللّٰهُ أنْ يَكُونَ، ثُمَّ يَرْفَعُها إذا شَاءَ أنْ يَرْفَعَها، ثُمَّ تَكُونُ مُلْكًا جَبْرِيَّةً، فَتَكُونُ ما شاءَ اللّٰهُ أنْ تَكُونَ، ثُمَّ يَرْفَعُها إذا شاءَ أنْ يَرْفَعَها، ثُمَّ تَكُونُ خِلافَةً عَلى مِنهاجِ نُبُوَّةٍ ثُمَّ سَكَتَ
“Prophethood will remain in you for as long as Allah decides for it to remain and then Allah will remove it when He decides to remove it. After prophethood, there will be a Khilafat on the path of prophethood and it will exist for as long as Allah decides for it to exist, then He will remove it when He decides to remove it. Then there will be a kingdom in which people will face trials and tribulations and it will continue to exist for as long as Allah decides for it to exist. Then He will remove it when He decides to remove it. After this, there will be an oppressive kingdom and it will continue to exist for as long as God decides for it to exist. Then He will remove it when He decides to remove it. Then there will once again be a Khilafat on the path of prophethood.” Thereafter he remained silent. (Musnad Ahmad bin Hanbal; Mishkat, Kitab al-Riqaq, Bab al-Andhar wal-Tahdhir)
The narrator of this hadith, Habib ibn Salim(rh), wrote a letter to Hazrat Umar ibn Abd al-Aziz(rh) (a reformer (mujaddid) of the first century) when he became the Khalifa and expressed the opinion that it was his rule that was foretold by the report. But in fact, this is a rather far-fetched idea as there had not passed the two mentioned distinct kingships before him.
This was also confirmed by the modern Salafi hadith scholar al-Albani (d. 1999 CE). He said:
ومن البعيد عندي حمل الحديث على عمر بن عبد العزيز، لأن خلافته كانت قريبة العهد بالخلافة الراشدة ولم تكن بعد ملكين ملك عاض وملك جبرية، والله أعلم
“It seems far-fetched to me to apply this hadith to Umar ibn Abd al-Aziz, because his Khilafat was close to the era of the rightly guided Khilafat, and there had not yet existed two kingdoms: a mordacious kingship (mulk ‘add) and a coercive kingship (mulk jabariyyah), and Allah knows best.” (Silsilat al-ahadith as-sahihah)
Another hadith that is corroborated by the above-mentioned hadith indicates that this Khilafat on the path of prophethood would be established with the appearance of the Mahdi. The Prophet(sa) said:
سَيَكُونُ مِن بَعْدِي خُلَفاءُ، ومِن بَعْدِ الخُلَفاءِ أُمَراءُ، ومِن بَعْدِ الأُمَراءِ مُلُوكٌ، ومِن بَعْدِ المُلُوكِ جَبابِرَةٌ، ثُمَّ يَخْرُجُ رَجُلٌ مِن أهْلِ بَيْتِي يَمْلَأُ الأرْضَ عَدْلًا كَما مُلِئَتْ جَوْرًا
“After me, there will be Khulafa. After the Khulafa, there will be rulers. After the rulers, there will be kings. After the kings, there will be tyrants. Then, a man from my ahl al-Bayt (progeny) shall emerge who will fill the earth with justice as it was filled with tyranny.” (Al-Mu‘jam al-kabir li-t-Tabarani, hadith 18406)
Contemporary non-Ahmadi scholars, such as Amin Muhammad Jamal ad-Din, Professor at the al-Azhar University in Cairo, and the famous Syrian scholar Muhammad al-Yaqoubi, have also expressed the opinion that this Khilafat on the path of prophethood would be established after the appearance of the Mahdi.
The consensus (ijma) of the Companions(ra)
The Companions(ra) of the Messenger(sa) of Allah agreed on the need to establish Khilafat through election after his death and to pledge allegiance to it. When Hazrat Abu Bakr(ra) was elected Khalifa after the Messenger(sa) of Allah, all the Companions pledged allegiance to him. Moreover, the Companions(ra) all agreed to elect the next Khalifa after the death of the respective previous Khalifa and pledge allegiance to him.
Furthermore, the general consensus of the Companions(ra) on the establishment of Khilafat became evident at the death of the Messenger(sa) of Allah, when they were dealing with the election of the Khalifa instead of preparing for his burial, although the burial of the deceased is obligatory, and it is not permissible to be preoccupied with anything else until the burial is completed.
This would not have been permissible unless the election of the Khalifa was a matter of greater obligation than the funeral. Moreover, throughout their lives, all the Companions(ra) agreed on the obligation of electing Khulafa and pledging allegiance to them. While there were times in early Islam when there was a difference of opinion on who should be elected Khalifa, there was never disagreement about the need to elect the Khalifa and pledge allegiance to him, neither after the death of the Messenger(sa) of Allah nor after the death of any of the rightly-guided Khulafa(ra).
Accordingly, the general consensus of the Companions(ra) is both clear and strong evidence that the establishment and election of the Khalifa and the pledge of allegiance to it are obligatory.
Also, the Companions(ra) of the Promised Messiah(as) agreed on the establishment of and pledging allegiance to the elected Khalifa. After the demise of Promised Messiah(as) all of the Companions(ra) unanimously pledged allegiance to Hazrat Hakim Maulvi Nuruddin(ra) as Khalifatul Masih I.
Thus, Khawaja Kamaluddin Sahib, who was the secretary of the Sadr Anjuman Ahmadiyya at the time, published the following notice to the members of the Jamaat in the supplement of the 30 May 1908 issue of Al Hakam newspaper, also signed by all trustees of Sadr Anjuman:
“The entire nation present in Qadian, numbering 1200 at the time, has accepted Hazrat Haji al-Haramayn al-Sharifayn Hakim Nuruddin as his [the Promised Messiah’s] successor and Khalifa, and has pledged allegiance at his hand. This letter goes as a notice to all the members of the Jamaat, that immediately after reading the letter, they should pledge allegiance to Hazrat Hakimul Ummah Khalifatul Masih wal-Mahdi, either in person or in writing.”
In the same way, the following announcement was published in the Badr newspaper of 2 June 1908:
“In compliance with instruction from the Promised Messiah, vide Al-Wasiyyat […] It has been decided that all members of the Jamaat, old and new, should pledge allegiance at his [Hazrat Hakim Maulvi Nuruddin’s] hand as Khalifatul Masih, in which capacity his wishes and orders shall have the same authority for us as the wishes and orders of the Promised Messiah.”
(Prepared by the Ahmadiyya Archive and Research Centre)