Allah Ta’ala has declared in the Quran Majid:

الْيَوْمَ أَكْمَلْتُ لَكُمْ دِينَكُمْ وَأَتْمَمْتُ عَلَيْكُمْ نِعْمَتِي وَرَضِيتُ لَكُمُ الْإِسْلَامَ دِينًا.
This day I have perfected for you your religion and completed My favor upon you and have approved for you Islam as religion

Listen to my lecture on this topic here