النُّبُوَّةُ كَائِنَةٌ لِإِصْلَاحِ نُفُوسِ النَّاسِ
Prophethood exists to reform human souls.
The primary purpose of prophecy is to reform human belief, devotion and conduct. Communities differ in their worship practices, habits, social arrangements and political conditions. Reform does not necessarily mean replacing every existing practice with something entirely novel.
An inherited custom that is sound and compatible with divine approval can remain. What conflicts with the purpose of guidance requires correction, modification or abandonment, according to the nature of the defect.
Thus changes in religious practice should be assessed in relation to the goal of human reform, not explained as novelty for its own sake.