Qur'an
Surah 2 2:138
صِبۡغَةَ ٱللَّهِ وَمَنۡ أَحۡسَنُ مِنَ ٱللَّهِ صِبۡغَةࣰۖ وَنَحۡنُ لَهُۥ عَـٰبِدُونَ ۝١٣٨
‘[Our life] takes its colour from God, and who gives a better colour than God? It is Him we worship.’

Allah said, if they, the disbelievers among the People of the Book and other disbelievers, believe in all of Allah's Books and Messengers and do not differentiate between any of them,
فَقَدِ اهْتَدَواْ
(then they are rightly guided) meaning, they would acquire the truth and be directed to it.
وَإِن تَوَلَّوْاْ
(but if they turn away) from truth to falsehood after proof had been presented to them,
فَإِنَّمَا هُمْ فِى شِقَاقٍ فَسَيَكْفِيكَهُمُ اللَّهُ
(then they are only in opposition. So Allah will suffice you against them) meaning, Allah will aid the believers against them,
وَهُوَ السَّمِيعُ الْعَلِيمُ
(And He is the Hearer, the Knower). Allah said,
صِبْغَةَ اللَّهِ
(The Sibghah of Allah). Ad-Dahhak said that Ibn `Abbas commented, "The religion of Allah." This Tafsir was also reported of Mujahid, Abu Al-`Aliyah, `Ikrimah, Ibrahim, Al-Hasan, Qatadah, Ad-Dahhak, `Abdullah bin Kathir, `Atiyah Al-`Awfi, Ar-Rabi` bin Anas, As-Suddi and other scholars. The Ayah,
فِطْرَةَ اللَّهِ
(Allah's Fitrah (i.e. Allah's Islamic Monotheism)) (30:30) directs Muslims to, "Hold to it."

((We take our) colour from Allah) i.e. follow the Religion of Allah, (and who is better than Allah at colouring) better than the Religion of Allah. (And We are His worshippers) say: we are monotheists and acknowledge that we worship Him and declare that there is only one true God.

EN

The mark of God sibghata’Llāhi a verbal noun reaffirming the earlier āmannā and it is in the accusative because of the verbal construction implied that is to say sabaghanā’Llāhu ‘God has marked us’ this denotes His religion the one towards which He made human beings naturally inclined as it leaves its mark on a person in the same way that a dye leaves its mark on a garment; and who has that is none has a better mark sibghatan ‘marking’ is for specification than God? And Him we worship the Jews said to the Muslims ‘We are the people of the first Book and our direction of prayer qibla is more ancient and prophets were never sent from among the Arabs; if Muhammad were a prophet he would have been one of us’. Thus the following was revealed

EN

The Colour of Allah
Verse 138 delineates Islam as the "colouring of Allah", and explains this "colouring" as the unalloyed worship of Allah and total submission to Him. Verse 135 has identified Islam with "the religion of Ibrahim." If we put Verse 135 and 138 together, it becomes clear that essentially Islam - or any authentic religion, for that matter – is the religion of Allah, and that the association of a religion with the name of a prophet can only be symbolised.
Verse 138 presents religion as "colouring" صبغہ (Sibghah). The expression carries within itself several levels of meaning. But the immediate allusion is to a certain ceremony of the Christians. On the seventh day of its birth, they used to bathe an infant in coloured (probably yellow) water, which was supposed to be a substitute for circumcision, and a sufficient guarantee for the external and internal purification of the infant - the fast and indelible "colouring" of Christian faith, so to say. The verse suggests that this colour is wasted away with the water, without leaving a trace outside or inside, nor does this kind of baptism serve the purpose of circumcision and cleanse a man of physical impurity. And the verse declares that the only colouring worth the name is the colouring of a genuine and unabrogated religion - that is, Islam اسلام۔ the only colouring which can guarantee physical and spiritual purification, and the only one which shall remain. Then, the word Sibghah صِبْغَةَ or "colouring" has a deeper meaning too. Just as a certain colour is openly and clearly visible to the beholder, the signs of genuine and pure 'Iman ایمان should shine through the face, the movements, the habits and the behaviour of a Muslim. In this sense, the verse is a commandment, asking Muslims "to dye" themselves in the "colouring of Allah", outwardly and inwardly by offering unalloyed worship to Him alone, by submitting themselves totally to His commandments, and by gladly accepting His will.

EN

If faith is to be of the kind which pleases God, it must be identical with that of the Companions of the Prophet. What was so special about that faith was that it amounted to acceptance of the truth on an abstract level; it was belief in truth for the sake of truth. This had become a rarity in a society which, revering the words of the ancient prophets, regarded as truth whatever had been sanctified by centuries-old tradition. Continued belief in such ‘truth’, embellished as it was by myth and legend, became a matter of national pride; to regard it in any other light would have been to deny a great legacy from the past. Unlike the ancient prophets, who were great figures, eulogised in their nations’ history, the Prophet Muhammad came afresh to the world with no accumulation of tradition behind him to lend weight to his words. When truth stands on its own, unsupported by history or tradition, as it was in the time of the Prophet, those who accept it do so for the pure and simple reason that it is the truth. This is the kind of belief that God recognizes and accepts. This is true faith; only faith of such strength and purity is acceptable to God.