Allah (Subhaanahu Wa Ta'Ala) always mentions the believers as one community, one brotherhood and one people. In the following ayah, Allah (Subhaanahu Wa Ta'Ala) mentions that the Muslims were made into one Ummah to be a witness over the other nations, and the Messenger - Muhammad (pbuh) - to be a witness over this Ummah.

"Thus have We made of you an Ummat justly balanced, that ye might be witnesses over the nations, and the Messenger a witness over yourselves; and we appointed the Qibla to which thou wast used, only to test those who followed the Messenger from those who would turn on their heels (from the Faith). Indeed it was (a change) momentous, except to those guided by Allah. And never would Allah make your faith of no effect. For Allah is to all people most surely full of Kindness, Most Merciful".[surah 2 (Al-Baqara), ayah 143]

Also in the following ayah, Allah (Subhaanahu Wa Ta'Ala) informs us that Muslims are the best nation, or Ummah:

كُنْتُمْ خَيْرَ أُمَّةٍ أُخْرِجَتْ لِلنَّاسِ تَأْمُرُونَ بِالْمَعْرُوفِ وَتَنْهَوْنَ عَنِ الْمُنْكَرِ وَتُؤْمِنُونَ بِاللَّهِ وَلَوْ آمَنَ

And again in the following ayat, Allah (Subhaanahu Wa Ta'Ala) mentions that the believers are a single brotherhood.

إِنَّمَا الْمُؤْمِنُونَ إِخْوَةٌ فَأَصْلِحُوا بَيْنَ أَخَوَيْكُمْ وَاتَّقُوا اللَّهَ لَعَلَّكُمْ تُرْحَمُونَ (الحجرات 10)

" The Believers are but a single Brotherhood: so make peace and reconciliation between your two (contending) brothers; and fear Allah, that ye may receive Mercy". [surah 49 (Al-Hujurat), ayah 10]

إِنَّ هَذِهِ أُمَّتُكُمْ أُمَّةً وَاحِدَةً وَأَنَا رَبُّكُمْ فَاعْبُدُونِ , وَتَقَطَّعُوا أَمْرَهُمْ بَيْنَهُمْ كُلٌّ إِلَيْنَا رَاجِعُونَ (الأنبياء 92 - 93)

"Verily, this Brotherhood of yours is a single Brotherhood, and I am your Lord and Cherisher: therefore serve Me (and no other). But (later generations) cut off their affairs (of unity), one from another: (yet) will they all return to Us." [surah 21 (Al-Anbiya'), ayat 92-93]

And in the following ayah, Allah (Subhaanahu Wa Ta'Ala) tells the believers to be united together and not to be divided reminds them that they were enemies but that Allah (Subhaanahu Wa Ta'Ala) saved them from this situation and made them into brothers:

"And hold fast, all together, by the Rope which Allah (stretches out for you), and be not divided among yourselves; and remember with gratitude Allah's favour on you; for ye were enemies and He joined your hearts in love, so that by His Grace, ye became brethren; and ye were on the brink of the Pit of Fire, and He saved you from it. Thus doth Allah make His Signs clear to you: that ye may be guided". [surah 3 (Al-Imran), ayah 103]

And in the following ayah, Allah (Subhaanahu Wa Ta'Ala) orders the Muslims and the believers to obey Allah (Subhaanahu Wa Ta'Ala) and His Messenger (pbuh) and not to fall into disputes because this will cause their power to be dissipated. We have seen this clearly illustrated in our situation today, were Muslims are the weakest and poorest of all nations. This has happened because we did not follow Allah's (Subhaanahu Wa Ta'Ala) commands in this ayah and we were separated into many nations and fought amongst ourselves.

"And obey Allah and His Messenger; and fall into no disputes, lest ye lose heart and your power depart; and be patient and persevering: for Allah is with those who patiently persevere. And be not like those who started from their homes insolently and to be seen of men, and to hinder (men) from the path of Allah: for Allah compasseth round about all that they do". [surah 8 (Al-Anfal), ayat 46-47]

And of course, when we are separated into countries and groups and fighting amongst ourselves, we take each other to be enemies and others outside the community of beleivers as freinds. This is what Allah (Subhaanahu Wa Ta'Ala) warns us against doing in the following ayah:

"Or think ye that ye shall be abandoned, as though Allah did not know those among you who strive with might and main, and take none for friends and protectors except Allah, His Messenger, and the (community of) Believers? But Allah is well-acquainted with (all) that ye do". [surah 9 (Al-Tawbah), ayah 16]

Later in the same surah, Allah describes the believers as "protector-friends" of each other:

"The believers, men and women, are protector-friends of each other, enjoining the correct and forbidding the incorrect." [surah 9 (Al-Tawbah), ayah 71]