Most religions are good, positive belief systems. The Christian gospels are a powerful plea for tolerance and humility. However, the fundamentally good core fails to prescribe a process that would allow a moral society to function.
Socially, all religions are authoritarian. Sadly you can't make people act morally by simply telling them to do so. In the real world even good people have conflicting interests, and an authoritarian "only one true answer" system can never resolve those conflicts successfully.
Liberal democracy may not be a very good system for resolving conflict, but at least it's a step in the right direction.