There are many ways to 'hear' about 'God'. There is only one way to know.
That is true. But it is also true that there are many ways to come to know God.
I happen to believe that anyone of any faith who actively seeks a relationship with God will come to know God.
Then how come I don't know god? I'm actively seeking (despite the stupid comment you're about to make

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Because you're looking for your concept of god, a concept that is so totally corrupted by our 'modern' environment that it cannot even be useful.
However mankind has imagined 'God', 'God', by simple definition of the fullest sense of that noun, could not be that. To be 'God' is to be undefinable, immense beyond measure in every conceivable sense of that word, in every direction and dimension. Otherwise, 'God' is nothing.
It is like the cliché Buddhist term; those who know, don't speak. Those who speak, don't know.
People ask if I believe in god, an easy question to throw out. Say yes, and you are dammed, and equally so with a "no". Notice the spelling there. "Dammed" is blocked, like a dam.
I could not, and would not for their own good, try to speak to others about what my vision of things is. There is, to me, something about the universe that makes me realize how people could believe in "God". That may not explain much, but it is about as close as I dare come.
P.S. Do not take this as saying 'God' does or does not exist. Only you can say.