In modern times, the fundamental assumption is that all religions are relatively equal in that they provide similar frameworks for ethics (though it is becoming ever clearer that this is not the case). In an age in which secular, non-affiliation is the norm, most hold that being religious in and of itself already sets a person up as someone who has at least some moral and ethical code. Furthermore, the general assumption is that everyone ends up in the same, and most assume this without realizing that the world religions paint vastly different pictures of what happens after death.
It is the case that doctrine and dogma are considered secondarily to exterior actions, most of which seem relatively similar. However, when we scratch the surface on all religions, the importance of dogma and doctrine, especially as it relates to salvation, is vitally important. Another way of looking at this is while what a person does is vital, why they do it is equally as important. Until modern times, inter-religious dialogue was centered around why the believers followed their path.
For Neoplatonists, it was union with the one. For Hindus, a similar trajectory of achieving union with the one. Each conceived of this union in radically different manners and for very different reasons. Furthermore, Buddhism and Taoism conceive of the ultimate realities in ways opposite to each other and the other paths. All shared a view that human activity is the fundamental locus of salvation, which is to say we save ourselves. Islam has a similar pelagian outlook.
Finally what sets Christianity apart is the view that it is grace offered through faith in Jesus Christ which is defining feature of salvation. This insistence on grace, predestination, and election as the fundamental truth of salvation is more important than even most Christians understand. As our Lord says, It is not you who chose me, but I who chose you. Of course, there is a bit of nuance, but we cannot delude that scripture and tradition points to grace as the primary means of attaining salvation and perfection. This grace is offered in the sacraments. I am going to be exploring these themes in some upcoming work. I am not sure yet what shape that this will take, but I hope you follow along for the ride.