As explained by Hazrat Khalifatul Masih IV (rh)
”The Muslims who should have been united and be in harmony, are divided in countless sects and divisions. It is not only in religious field but in politics too. When there is schism, they can achieve nothing in the world, which a united and harmonious people can do. By discord and disharmony the power of the Muslim world has not only disintegrated, but also they are using this broken strength against one another. When such are the conditions, the aggregate will be below zero.
The groups may be very powerful, but if they will oppose and counteract each other in minor and major issues and remain busy in fighting, their power will be scattered and strength broken.
This is happening in every Muslim country. Unfortunately it is being named as Jihad. What will they gain from all this? What resources will remain for their own nation building, defense of Islam or fighting the enemy? Therefore, it is incumbent that Muslims should unite on the hand of One Imam. There should be one Imam of the Muslims of the whole world. But without Khilafat, it is just impossible. Khilafat is the successor after the prophet in the form of a person who is representing the deceased prophet and Khalifa is the vicegerent and his subordinate. He is the central authority. This is the basic principle of Khilafat.
Muslims do understand its need as well as importance. This need was felt after the sad demise of the Holy Prophet ﷺ also. In Islam this is quite clear like broad daylight and is a part of Islamic teaching that without unity and harmony you cannot rightly work on the teachings of Islam. When you go to the mosque for Namaz five times a day, there must be an Imam. Standing behind an Imam is a demonstration of unity among people. That is why the Holy Quran especially emphasizes the need of congregational prayer. Imam is given so much importance that if the Imam falters, the entire congregation must follow his mistake even if they know that a mistake has been committed. What better instance can be presented for the need of an Imam and unity in his following? If Imam is mandatory in a small mosque, then how can the whole of Muslims Ummah survive without an Imam.
As far as the Ummah is concerned, there is commandment in the Holy Quran to turn their faces towards Qiblah. For the Muslims throughout the world, there is one and only one Qiblah. You may go anywhere in the world, the Qiblah remains the same. This is a pointer that it is incumbent for the Muslim Ummah that they should be united under one Imam. Had this not been the sole purpose, there would have been no Khilafat at all because the spiritual condition of Muslims in the days of the Holy Prophet was a thousand times better than the Muslims of today. If they need to follow an Imam, how can we live without an Imam today when the condition of Muslims is crying for it. This is the answer why Khilafat is needed.”
Extract taken from Ahmadiyya Gazette, Canada. Khilafat Number, May 2001