You are expressing the common, but inaccurate, notion that there is a distinction between “knowledge” and “belief.” Again EVERY idea we have is a belief. Even the idea “I exist” is a belief. Understanding this is vital so that we can get past the fallacy of “I have knowledge, you have only a belief.” We can replace that obfuscation with the fruitful discussion of what are the justifications of beliefs. There is no such thing as absolute, inviolable “knowledge.” We have more useful and less useful ideas. https://medium.com/inserting-philosophy/who-are-you-you-are-your-beliefs-7ab14afa7e07