Since all of this is fairly common knowledge, one might ask if you are sincere in your question or whether you are simply trying to catch an atheist. Be assured that atheists have very good reasons for their convictions and the vast number of “true ways to heaven” is one very good reason to throw in the towel re religion. Of course, that’s not why I deconverted, but I’m just saying.
That depends who you ask. There are tens of thousands of Christian denominations, each of which believe they have the Only True Way. Then there is Islam and Judaism, both of which have drastically different ways to heaven. But the Nordic Religions of pre-Christian Europe are yet different. Then there are the Aztec religion, and thousands of other religions throughout the world, across time and geography, each of which is convinced about having the only right way.