Children cannot understand and choose Christ. They have Christ chosen for them. Mostly by their parents through church indoctrination.
If god exists, and hell exists, then god is completely unreasonable expecting everyone to believe in a savior that there's zero evidence for. Imagine for a moment if you will the Christianity is not true, and that instead we are all judged by whether or not we believe in Shiva. It doesn't matter what else you do in your life, no matter how good of a person you are, you go to Naraka. Does Shiva sound reasonable with this expectation? You can bring up personal revelation all the time, but if personal revelation was true (and many believe it's true for their religion too) then you'd find groups of people who never encountered civilization with a belief in Jesus.
If god exists, and hell exists, then god is completely unreasonable expecting everyone to believe in a savior that there's zero evidence for. Imagine for a moment if you will the Christianity is not true, and that instead we are all judged by whether or not we believe in Shiva. It doesn't matter what else you do in your life, no matter how good of a person you are, you go to Naraka. Does Shiva sound reasonable with this expectation? You can bring up personal revelation all the time, but if personal revelation was true (and many believe it's true for their religion too) then you'd find groups of people who never encountered civilization with a belief in Jesus.