Relativists: if truth is relative and no religion is absolutely true, how do you know?

Here is a short story. Six blind men approach an elephant. They feel it and grab it to try and decide what it is. one man grabs the tail and says the elephant is wiggly, skinny, and long. another man grabs a leg and says its short and round. another man grabs the tusk and says its smooth, pointy and curved. as you can imagine the rest of the men also grab different parts of the elephant and make claims on what the elephant is. each man has a different take on what the elephant looks like based on what parts of the elephant they touched. The elephant as a whole is a symbol for TRUTH. The different body parts and conclusions made by the blind men are interpretations of the truth. the problem is each blind man is unable to discover what the elephant truly looks like. For anyone PERSON to say that all religions are true but each one is not perfect is no different than one of the blind men. For anyone to ever make the claim that even a single religion is false or lacking something is to claim that they have the spiritual superiority to know what the truth is in order to make such a claim. You cannot say a religion is false unless you know what the truth is. So in a sense anyone who says that one or more religions are imperfect is making a claim that they have a better perception on what the truth is. that is an exclusive belief. that person is suggesting that they have superior knowledge than someone else who believes otherwise. An open minded person should be humble enough to admit they solely do not have a monopoly on truth so to discredit a religion and or exclusive belief system like Islam, Christianity, Judaism, etc... At least exclusive religious people know and admit they are exclusive in their beliefs.