Why an interest-free economy was instituted from early religious zeal?

Throughout the 20th century, proponents of Islamic economics put forward the establishment of a modern banking system (and Islamic economic system) that adhered to Sharia principles and banned all forms of riba (interest). Greater attention was given by various reformist scholars to Islamic banking and finance in the 1960s and 1970s, and has continued to grow since then. The restriction on riba also prevailed even among non-Muslims and the origins of interest prohibition can be traced to the Jewish and Christian faiths. However, the issue of prohibiting interest in modern financial systems is still a matter of debate among Islamic jurists and often causes confusion and inconsistency as to cases when riba can be applied. While riba is expressly prohibited in all aspects of religion in a classical religious context, the modern practice of the interest system in Islamic finance is still debated in the context of a contemporary society.