For me it was based on logic and simplicity. If God could talk, he would. There are people who can talk but refuse not to out of anger or trauma or something. It's been thousands of years and only in the bible has God spoken and since it's the bible people believe they cannot speak against the claim. If God is truly all powerful, then with such power should come something as easy as the language people profess that he gave us. Logic dictates that if you have everything you need and want to accomplish something and you do not put in the effort, you either didn't want it, or can't do it. Since god has "spoken" to so many people, shouldn't he speak to us all so we all get the same message. If we do not hear him based on our own faults, then it says that because of us, he can't talk to us, or he is clearly not all-powerful. I hope this helps you understand my side of things a bit more. I know it was long. Thank you for reading.