Have you not seen those who claim to have believed in what was revealed to you, -Quran Verses

4-Surah An-Nisa ( The Women ) 60

Have you not seen those who claim to have believed in what was revealed to you, [O Muhammad], and what was revealed before you? They wish to refer legislation to Taghut, while they were commanded to reject it; and Satan wishes to lead them far astray.

﴿60﴾أَلَمْ تَرَ إِلَى الَّذِينَ يَزْعُمُونَ أَنَّهُمْ آمَنُوا بِمَا أُنزِلَ إِلَيْكَ وَمَا أُنزِلَ مِن قَبْلِكَ يُرِيدُونَ أَن يَتَحَاكَمُوا إِلَى الطَّاغُوتِ وَقَدْ أُمِرُوا أَن يَكْفُرُوا بِهِ وَيُرِيدُ الشَّيْطَانُ أَن يُضِلَّهُمْ ضَلَالًا بَعِيدًا

Quran's Tafhim ( explanation)

*91). Taghut clearly signifies here a sovereign who judges things according to criteria other than the law of God. It also stands for a legal and judicial system which acknowledges neither the sovereignty of God nor the paramount authority of the Book of God. This verse categorically proclaims that to refer disputes to the judgement of a court of law which is essentially taghut contravenes the dictates of a believer's faith. In fact, true faith in God and His Book necessarily requires that a man should refuse to recognize the legitimacy of such courts. According to the Qur'an, belief in God necessitates repudiation of the authority of taghut. To try to submit both to God and to taghut at the same time is hypocrisy.