The promise of Allah to establish the Khilaafat

Wa adal la_hul lazina a_manu_ minkum wa amilus sa_liha_ti layastahlifan nahum fil ardi kamas tahlafal lazina min qablihim wa layumak kinan na lahum dinahumul lazir tada_ lahum wa layubad dilan nahum min badi haufihim am na_ yabudu_nani la_ yusriku_na bi sai a_ wa man kafara bada za_lika fa ula_ ika humul fa_siqu_n. Wa aqimus sala_ta wa a_tuz zaka_ta wa atiur rasu_la la'al lakum turhamu_n
Allah has promised to those among you who believe and work righteous deeds that He will of a surety grant them in the land inheritance (of power) as He granted it to those before them; that He will establish in authority their religion the one which He has chosen for them; and that He will change (their state) after the fear in which they (lived) to one of security and peace: `They will worship Me (alone) and not associate aught with Me. ' If any do reject faith after this they are rebellious and wicked. So establish regular Prayer and give regular Charity: and obey the Apostle; that you may receive mercy. [24:56, 57]

Al lazina im makkannaa_hum fil ardhi aqaa_mus salaa_ta wa aa_tawuz zakaa_ta wa amaru_ bil ma'ru_fi wa nahau anil munkar wa lillaa_hi 'aa_qibatul umoor
The promise of the establishment of Khilaafat is clear and unmistakable. As the Holy Prophet Muhammad sallallahu alayhi wasallam is now sole guide of humanity for all time, his Khilaafat must continue to exist in the world till the end of time. This is distinct superiority of the Holy Prophet Muhammad sallallahu alayhi wasallam over all other Prophets and Messengers of Allah.
The boon of Khilaafat will be bestowed upon them and they will be made the leaders of Ummah; their state of fear will give place to a condition of safety and security, Islam will reign supreme in the world, and above all the Oneness and Unity of Allah - the real purpose and object of Islam - will become firmly established.