There was a time when I could easily have been brought to believe in the supposed reality of the christian god. He would only have had to show up. Had a spiritual being manifested himself in my presence, I would not have been inclined to ask questions. That’s no longer true today. I have become more suspicious and would want to check against the possibility of an imposter. Also, I have become convinced that the christian god in particular is not real.
Face-to-face communication is always the most persuasive. If you want to reach someone, you do it face-to-face unless there is some compelling reason why you cannot do so. For example, I type this in advance because I need to compose my thoughts. But the more indirect a communication is, the less believable it is. A being who could supposedly speak the world into existence could certainly take some time to sit down with each person individually and give any message that he wished. But he has never sat down with me. It’s not even a "no second chances" concept. There was never a first chance. And the claims made by proselytizing christians don’t even pass the smell test. They will claim that the bible is "god's personal letter to you." As a point of fact, if you give the same letter to thousands of people, it is not a personal letter, it is a form letter.
And what is the reason this god doesn't show up individually? I have asked before if he is just too busy these days. Interestingly, that would be an acceptable justification -- if incompatible with the other claims made for this being. But I get excuses like "he doesn't want to force people to believe in him" and "he showed up thousands of years ago; that was the opportunity." These are not persuasive to me. At best, it suggests a god who is playing games. But it's more likely that he never showed up to anybody. The writing claiming that he did is fictional. Bluntly put, if the biblical god were real, there would be no need for the bible.