Sharia and Islam constitute one of the key indices in the current Nigerian constitutionalism and democracy project. Although it has made a considerable inroad into the nation’s grundnorm, Islamic law still seeks to extend the prongs of its justice system beyond the jurisdictional scope granted it by the 1999 constitution. The effect is that criminal and other aspects of the legal regime have been adopted by most states in nothern Nigeria but not without an affront to the secularity principle that should undergird national affairs. This paper examines the socio-economic and political implications of the extended sharia on human rights of Muslim and non-Muslim citizens. It also seeks to juxtapose the adoption of Islamic criminal law with the role a religion and its laws should play for national integration and social cohesion. The study equally suggests ways by which Nigerian Islamic law and religion would be made to join in winding the wheel of progress of Nigerian democracy. The methodology employed is largely structural-functional and jurisprudential.