Qur'an 10:104

قُلْ يَـٰٓأَيُّهَا ٱلنَّاسُ إِن كُنتُمْ فِى شَكٍّ مِّن دِينِى فَلَآ أَعْبُدُ ٱلَّذِينَ تَعْبُدُونَ مِن دُونِ ٱللَّهِ وَلَـٰكِنْ أَعْبُدُ ٱللَّهَ ٱلَّذِى يَتَوَفَّىٰكُمْ ۖ وَأُمِرْتُ أَنْ أَكُونَ مِنَ ٱلْمُؤْمِنِينَ

Say (O Muhammad): O mankind! If ye are in doubt of my religion, then (know that) I worship not those whom ye worship instead of Allah, but I worship Allah Who causeth you to die, and I have been commanded to be of the believers.