I believe that religion is what humans call the "important ideas" in life. That is, I think religion is the term that we all use to explain how we fit into life. Since we fit into the world in different ways, we have different things to say about how our lives have meaning. What I have to say about where I fit into the world is different from what a Christian may have to say about where they fit into the world, and we'll both differ with an atheist in how we fit into the world. We all say different things and use different words, but we're all trying to answer the same question.
This does not make me any more tolerant than a fundamentalist Christian who believes that religion is about salvation through Christ. Beliefs about the correctness or validity of other religions doesn't make any of us more inclusive, or tolerant, or sophisticated than other religions that disagree with us. While no one ever makes such a bald statement, it is implicitly said by a number of Pagans -- all who explain that since they believe all religions are valid, others should accept their religion, too.
Tolerance isn't about belief; it's about action. Tolerance isn't about accepting the validity of a religion; it's about politeness when interacting with other religions. Being tolerant of another's religion does not imply that a person believes it is valid, nor does believing a religion is valid necessarily imply tolerance of the religion. Tolerance is about following the social norms of polite society when interacting with other religions, and about giving all religions, within reason, freedom to practice without legal hindrance.
It's not important that people outside of our religions think that our religions are valid. What's important is that they, at a minimum, don't interfere with our ways of honoring our Gods and living correctly. While I happen to believe that all seekers, religious or not, are finding their Truth and learning about how they relate to the world, it doesn't affect my search if they disagree. More importantly, if I try to convince another person that my religion is valid, when their religion says otherwise, I'm proselytizing -- that is, trying to convince them that a religious belief that I hold is one they should believe, too. While one can proselytize politely, it requires an expression of interest from the other person. An expression of mild interest in what one's religion is doesn't qualify as enough interest to begin proselytizing.
This means that if that religion believes that it is the only way, I ignore that part of the religion for the duration of my discussion with a participant from that religion. If the participant of that other religion happens to be rude enough to raise that issue and personalize it, the proper response is not for me to try to convince them that they're wrong, or that I'm superior because I accept their religion as valid. The proper response is to express a willingness to disagree and then to change the subject. If the topic resurfaces, it is dealt with ever-firmer changings of the subject, or a termination of the conversation.
Many Neopagans seem to think that if they repeat the mantra that "all religions are the same," they'll eventually manage to convince others that their particular expression of this "universal religion" is also valid. But denying differences in religions doesn't further interfaith efforts; it merely muddies the waters. A Neopagan who isn't Wiccan doesn't feel particularly charitable to Wiccans after one blithely tells a reporter that "All Neopagans worship the God and the Goddess," or "All Neopagans cast circles," and the statement "Christians and Pagans really believe the same thing," is unlikely to start a conversation out on the right foot with a fundamentalist Christian. At best, it's likely to arouse mild ire. At worst, it arouses ugly and angry feelings that inhibit further interactions. Further, what makes religious discussions interesting isn't citing a laundry list of things two religions agree on. What makes religions interesting is the differences of theology, belief, and practice that each one brings to the discussion. As my husband once said, people who join tall clubs don't stand around talking about how they're all tall -- to do so would be incredibly uninteresting. Religious discussions between two people of different religions shouldn't only cover the things that they agree on -- to do so reduces each religion to a one-dimensional shadow, devoid of color and form.
Tolerance means that you don't define your religion by saying, "I'm not like those people over there." It means that you describe what you believe and practice in positive terms, with as little reference to other religions as possible. To assist in descriptions of unfamiliar practices, other religions' practices may be offered as analogous to particular practices of yours. This should be done as sparingly as possible, and only if you are familiar enough with the analogous practice to know that doing so wouldn't be an affront to a majority of the adherents. So, for example, while it might be appropriate to say, "I use a Circle of Stones, which is a meditation and prayer device similar to a rosary," it is not appropriate to say, "I am not a Satanist and I don't sacrifice animals," or "Unlike Christians, I don't proselytize." In particular, these latter statements presume to define others' religions for them; a privilege that singularly belongs to adherents of those religions. After all, we wouldn't appreciate someone making equivalent assertions about our religions while defining theirs.
Tolerance means that one starts with the assumption that the people being addressed will believe you to be a basically decent and normal person. To do otherwise only creates stereotypes where there were none before or causes people to wonder why a particular religion seems so defensive. Similarly, tolerance also means that one starts with the assumption that the people you are addressing are basically decent and normal people. Discovering otherwise after the conversation begins is grounds for ending the conversation.
I'm not sure that belief in the validity of other religions is really a useful one -- it often seems to be used to judge our religion as superior to others. I think a truly wise pluralistic society is one where religions just don't have a lot to say about each other. My answer to the cosmic question of "Who are you, and how will you live?" isn't concerned with the "rightness" of other people's answers. Finding this answer is the purpose of my religion, and while I believe that other people's religion attempts to answer the same question for them, this belief doesn't much help me discover who I am or what my purpose in life is. I think that too many people focus too much on the pluralistic aspect of their religion. While that might produce good feelings for those new to the faith, it only minimally helps answer the question of "how to live", and moves one little closer to finding their unique place and purpose in the universe.