Allah has made this known in the Quran since before the creation of man on earth. In surah Al-Baqarah 2:30 Allah mentioned:
'And [mention, O Muhammad], when your Lord said to the angels, "Indeed, I will make upon the earth a successive authority." They said, "Will You place upon it one who causes corruption therein and sheds blood, while we declare Your praise and sanctify You?" Allah said, "Indeed, I know that which you do not know."'
Indeed Allah knows what others don’t know. Since Adam (A.S), Allah has taught man the knowledge needed to manage the world in peace by giving us the religion/system of peace or in other words ‘Islam’. Allah continues in the following verse 2:31:
'And He taught Adam the names – all of them. Then He showed them to the angels and said, “Inform Me of the names of these, if you are truthful.”'
However, over time, man has forgotten his role as the khalifah on earth and started to make disruptions to other human beings and Allah’s creations. These disruptions are even happening in a smaller proportions closer to us. We see people backbiting, slandering each other and creating all sorts of evil-doing which result in division among us.
Actually we forget that Allah has created us as one community and all of us come from one family line - Adam and Hawa - which was created by one creator - Allah. Allah stressed in the Quran in Surah Yunus 10:19:
'And mankind was not but one community [united in religion], but [then] they differed. And if not for a word that preceded from your Lord, it would have been judged between them [immediately] concerning that over which they differ.'
Every time we forgot and become divided due to differences in perceptions/ opinion, Allah appointed among us a prophet/prophets to establish religion/ system of peace and unite us again. That is the role of all prophets. Allah instructs in the Surah Ash-Shuraa 42:13:
'He has ordained for you of religion what He enjoined upon Noah and that which We have revealed to you, [O Muhammad], and what We enjoined upon Abraham and Moses and Jesus - to establish the religion and not be divided therein. Difficult for those who associate others with Allah is that to which you invite them. Allah chooses for Himself whom He wills and guides to Himself whoever turns back [to Him].'
If we observe closely, we can summarise the situation in which Allah mentioned in the ayah above as in the diagram below.
Every time the system of peace falls, the community becomes divided. The repercussion can be seen in the breakdown of the community at all levels be it social, cultural and even at the administration level. The continuous rise and fall of the system of peace is a Sunnatullah/Allah’s resolution(decree, ketetapan). The final of all prophets, Muhammad S.A.W brought the system to its height and then it has fallen again after the Uthmaniah Empire. And now, who has to play the role in establishing the system of peace and unite the ummah/community (from all walks of life)?
Observe and read the ayah closely, Allah says ‘He has ordained for you’, meaning, the task is also given to the all of us who read the Quran. Allah strengthens this in Surah Yunus 10:14:
'Then We made you successors in the land after them so that We may observe how you will do'.
In order to perform the task, we have to be united and understand that Allah created us as one. Nevertheless, even the prophets did not do it alone and had help from his auliya(disciples)( As-Saff 61:14). Allah created difference colours, races and tribes only to test us and allow us to learn from each other. Not for us to be proud of our race and differences but what is more important for Allah is those who are most righteous among us and perform the task given to him/her. He reminds us in Surah Al-Hujurat 49:13:
'O mankind, indeed We have created you from male and female and made you peoples and tribes that you may know one another. Indeed, the most noble of you in the sight of Allah is the most righteous of you. Indeed, Allah is Knowing and Acquainted.'
No matter how far we are from one another, we are but one. In order for us to be united in performing our tasks in establishing the system of peace as the Khalifah on earth, we have to always focus on the similarities among us and not on the differences/varieties that Allah created. In Surah Mu’minun 23:52-54 Allah says:
'And indeed this, your religion, is one religion, and I am your Lord, so fear Me.
But the people divided their religion among them into sects - each faction, in what it has, rejoicing.
So leave them in their confusion for a time.'
Nauzubillah. May we are always be guided and not left in confusion by Allah.