The Quran

إِنَّ الَّذينَ آمَنوا وَالَّذينَ هادوا وَالصّابِئينَ وَالنَّصارىٰ وَالمَجوسَ وَالَّذينَ أَشرَكوا إِنَّ اللَّهَ يَفصِلُ بَينَهُم يَومَ القِيامَةِ ۚ إِنَّ اللَّهَ عَلىٰ كُلِّ شَيءٍ شَهيدٌ

Muhammad Asad

Verily, as for those who have attained to faith [in this divine writ], and those who follow the Jewish faith, and the Sabians,¹ and the Christians, and the Magians,² [on the one hand,] and those who are bent on ascribing divinity to aught but God, [on the other,]³ verily, God will decide between them on Resurrection Day: for, behold, God is witness unto everything.

See surah 2, note 49.
Al-majus: the followers of Zoroaster or Zarathustra (Zardusht), the Iranian prophet who lived about the middle of the last millenium n.c. and whose teachings are laid down in the Zend-Avesta. They are represented today by the Gabrs of Iran and, more prominently, by the Parsis of India and Pakistan. Their religion, though dualistic in philosophy, is based on belief in God as the Creator of the universe.
The Christians and the Magians (Zoroastrians) are included in the first category, for although they do ascribe divine qualities to other beings beside God, they regard those beings, fundamentally, as no more than manifestations - or incarnations - of the One God, thus persuading themselves that they are worshipping Him alone; whereas "those who are bent on ascribing divinity to beings other than God" (alladhina ashraku) by obvious implication reject the principle of His oneness and uniqueness.