Here's the thing about truth, in order for anything to be true it must exclude things that are false. Either president Obama is the president or he isn't. Obama can't be the president, and not the president at the same time. This violates the law of non contradiction, anything that is a contradiction is false, therefore it's not truth. To find any truth it must exclude things that are contradictory to it. Truth by definition is narrow.
Joan Rivers made a statement "I believe you can believe what you want to believe". Your beliefs do not create truth. The new age spirituality movement believes that the earth and universe is identical with divinity, meaning that God is in all creation. We now have 100 years of scientific evidence that the universe is not eternal. Click here to read. God by definition is an eternal being, therefore the new age spiritual movement is not true, making it false. You see if the new age movement were true, the universe would be eternal and could be divine. But it's not. The universe began to exist at a certain point in time and will end at a certain point in time. This is a logical contradiction and truth must exclude things that are contradictory to it. Bottom line is, your beliefs do not create truth. You can believe in a lie. A lie believed is still a lie.
Joan Rivers statement is what you call "religious pluralism". All religions are the same. But here's the truth. All religions are not the same. All religions do not point to God. All religions do not say that all religions are the same. At the heart of every religion is an uncompromising commitment to a particular way of defining who God is or is not and accordingly, of defining life’s purpose. Anyone who claims that all religions are the same betrays not only an ignorance of all religions but also a caricatured view of even the best-known ones. Every religion at its core is exclusive and making a claim about truth.