Al-Baqara 2:143

Thus We made you a balanced nation, so that you may be witnesses over mankind and the Messenger a witness over you. We did not change your former direction of prayer [to the Ka‘bah] except to distinguish those who would follow the Messenger from those who would turn back on their heels. It was surely burdensome except for those whom Allah guided. Allah would never let your [acts of] faith go to waste, for Allah is Most Gracious and Most Merciful to all people.

And thus We have made you a median [i.e., just] community that you will be witnesses over the people and the Messenger will be a witness over you. And We did not make the qiblah which you used to face except that We might make evident who would follow the Messenger from who would turn back on his heels.[52] And indeed, it is difficult except for those whom Allāh has guided. And never would Allāh have caused you to lose your faith [i.e., your previous prayers]. Indeed Allāh is, to the people, Kind and Merciful.

[52] i.e., refuse.

143. Thus We have made you [true Muslims - real believers of Islâmic Monotheism, true followers of Prophet Muhammad صلى الله عليه وسلم and his Sunnah (legal ways)], a just (and the best) nation, that you be witnesses over mankind[29] and the Messenger (Muhammad صلى الله عليه وسلم) be a witness over you. And We made the Qiblah (prayer direction towards Jerusalem) which you used to face, only to test those who followed the Messenger (Muhammad صلى الله عليه وسلم) from those who would turn on their heels (i.e. disobey the Messenger). Indeed it was great (heavy) except for those whom Allâh guided. And Allâh would never make your faith (prayers) to be lost (i.e. your prayers offered towards Jerusalem). Truly, Allâh is full of Kindness, the Most Merciful towards mankind.

[29] (V.2:143) Narrated Abu Sa‘îd Al-Khudrî رضي الله عنه: Allâh’s Messenger صلى الله عليه وسلم said "Nûh (Noah) will be called on the Day of Resurrection and he will say, ‘Labbaik and Sa‘daik, (I respond to Your Call and I am obedient to Your Orders) O my Lord! Allâh will say, ‘Did you convey Our Message of Islâmic Monotheism?’ Nûh (Noah) will say, ‘Yes’. His nation will then be asked, ‘Did he convey Our Message of Islâmic Monotheism to you?’ They will say, ‘No warner came to us.’ Then Allâh will say [to Nûh (Noah)], ‘Who will bear witness in your favour?’ He will say, ‘Muhammad صلى الله عليه وسلم and his followers.’ So they (i.e., Muslims) will testify that he conveyed the Message - and the Messenger (Muhammad صلى الله عليه وسلم) will be a witness over you, and that is what is meant by the Statement of Allâh عز وجل: We made you [true Muslims - real believers of Islâmic Monotheism, true followers of Prophet Muhammad صلى الله عليه وسلم and his Sunnah (legal ways)] a just (and the best) nation that you be witnesses over mankind and the Messenger (Muhammad صلى الله عليه وسلم) will be a witness over you." (Sahih Al-Bukhâri, Vol.6, Hadîth No.14).

Thus We have appointed you a middle nation, that ye may be witnesses against mankind, and that the messenger may be a witness against you. And We appointed the qiblah which ye formerly observed only that We might know him who followeth the messenger, from him who turneth on his heels. In truth it was a hard (test) save for those whom Allah guided. But it was not Allah's purpose that your faith should be in vain, for Allah is Full of Pity, Merciful toward mankind.