In this concluding chapter, we summarize of the main themes and ideas in the preceding chapters before considering the challenges the Islamic financial services industry is facing in the second decade of the twenty-first century. The first contribution of this book is that we have sought to connect the Islamic banking theories to the rich conceptual framework already developed over some five decades that form the basis of research (and graduate courses) on conventional banking and financial intermediation, in particular, information asymmetries, adverse selection, moral hazard, agency theory, optimal contract design and incentive structures.