When someone asks me this question, I find it helpful to have them participate with me in a reasoning process, instead of flat out saying “no” or jumping to “Jesus said I am the Way, the Truth, and the Life.”
I first propose there are three possible answers to that question: “yes,” “no,” and “sort of.” That would seem to encompass the entire range of possibilities. Now, the answer implied in the question when it is stated this way is “yes.” However, ask the person you are in the conversation with to consider the possibility of “sort of” or “no.”
The issue with the statement that all paths leads to God is that many of the major world religions make exclusive claims about their Gods and therefore point toward other gods as being lesser than or unreal. Islam certainly says there is no God other than Allah. Judaism says there is no God other than Yahweh, and Christianity says that Jesus is the one and only Lord of the universe. One may say that these three faiths all worship the same God but just call him different things. But then there is Buddhism, which insists that there is no God, while Hinduism insists there are many gods. Not all of these can be true at the same time. It is a logical impossibility. And the existence or non-existence of one or many gods, and their names and character are absolutely essential core statements of faith. It’s not as if were are arguing about peripheral issues here: the central ideas of these religions differ immensely.
In response, one might say then “Well, every religion has aspects of truth to them. No one religion is entirely right.” This is a valid option, and in fact on a purely logical basis, we would have to admit that this very well could be true. We do know that nearly all of the faith traditions of the world encapsulate very noble teachings and aspirations, and each has distinctives that people of other faiths can learn from. The question about this option, however, is how do we decide which teachings from which religion are correct? We are left grappling with a buffet approach to religion: one person may look at all the various teachings and ideas and put together one kind of plate, and someone else something entirely different. Even if each person’s melange of ideas didn’t conflict within themselves, at some point that certain concoction will conflict with someone else’s, leaving us with the question of who is right. Or, more importantly, what gives any person the right to pass judgment on the beliefs of traditional religions and other’s ideas and to make truth claims? What makes one person’s version of truth better than another’s? — a question that cannot be ignored when these mixtures conflict on certain key points.
So your conversation partner will either have to provide a logically defensible answer to that question or move on to the “no” possibility. The “no” means that either no religion is right and we should just stop worrying so much about it and move on, OR that one religion stands out above the others as providing the true way to access God. Which option to chose and which religion that might be could be left to another series of conversations.