Universalism posits that all religions lead to the same destination as long as the adherent is sincerely following whatever religion. Universalists like to point to the fact that people all have different "starting points" in life . The two primary examples given is geographical location and culture- both can be barriers to receiving information about the "correct" worldview. They believe that this is not fair, and since they project their idea of "fairness" onto any deity that might exist (see my previous series "God: Your Way, Right Away"), they conclude that exclusivistic religions are not correct. They also say that since there are many ways that one can go to reach a physical destination, this must be the same with regards to the religions.
The first problem that I see with this is the assumption that people all begin at different points spiritually. The claim is that since we start at different points in our physical life, this must be the same for our spiritual life. This has not been demonstrated. Now to be charitable, the converse cannot be demonstrated either (that we start from the same point spiritually); however, many things to point to the truth of the converse.
Let me talk about the analogy of taking different paths to a destination. Just because someone may take different routes to the local grocery store, does not mean that one may take different routes to get to Heaven. I would agree that people will take different paths to reach the conclusion that a certain religion is correct (has the correct path to heaven); but from that point, the idea that different paths may be taken is nullified. Here's the analogy- Just like looking for milk at the grocery store, we may take different roads to get to the store and go through different entrances and paths in the store to get to the aisle with the milk (where the universalist stops with the analogy- but let me take it further); but we all must come down the same aisle, open the same door, and get the milk from the same direction (we can't reach from behind to get it). The "multiple paths to the milk" analogy still comes down to a single path to obtain it.
The second problem I have with universalism/inclusivism has to do with its definitions of the end points. All the religions of the world have a specific definition of what the final end point is and what it is not. Many of these religions' definitions of the final end point is in contradiction with another religion's final end point. For instance, Hinduism posits that the final end point is that the self is absorbed into the Brahma and not longer possesses individual existence. The theistic religions' final end point (for believers) posit being in the presence of God and instead of losing individuality, maintaining individuality. Since these two are in stark contrast, a universalist/inclusivist must alter one or both of the religions' final end point definitions- which changes the religions in such a way that they are not the original religions. The universalist/inclusivist has eliminated the original religion from being correct by changing the definition of the final end point to his/her own. The universalist/inclusivist is exercising exclusivism by eliminating even one original understanding of a religion. Universalism/inclusivism is not even possible as it is "practiced" today.
In order for a universalist/inclusivist to truly practice such a "faith", they must never question or doubt the truth of any understanding of any of the world's religions, including the exclusivistic ones. If they truly believe that every religion leads to the same destination, then having conversations about religion is truly a waste of time.
Looking at my objections here again...it almost looks as though these are just implications and observations that don't really point to the validity of universalism/inclusivism. I mean, universalism/inclusivism could still be true regardless of my objections, right? Not really- for two reasons. First, in order for universalism/inclusivism to be true, no belief may be rejected (everyone can think of at least one belief that is to be rejected). Second, by identifying its own position, it has defined itself as being opposed to other beliefs. In order for even the possibility of universalism/inclusivism to be true, it must remain unidentified, unnamed, undefined, and unarticulated.