The Quran has enjoined on the Muslim to abide by the Islam in its completeness. Patch work is not allowed. The Quran says "O believers, come to the grace of peace and security. Do not follow in the footsteps of Satan your acknowledged enemy. If you falter even after Our Signs have reached you, then do not forget that God is All-powerful and all-wise". (Quran 2 x 208-209)