The only reason why ancient aliens (in the sense of intelligent aliens that had visited and had been recorded by humans) is more plausible than Christianity is the key players of the former - intelligent extraterrestrials beings - is vastly more likely to exist, somewhere, than the key player of the other - god that fits the descriptiom of those who say god have revealed himself to them.
But other aspect of ancient aliens stories - visitation during historic times and were recognizably recorded as such by ancient humans - are on par in its demand upon gullibility as divine revelation.
But other aspect of ancient aliens stories - visitation during historic times and were recognizably recorded as such by ancient humans - are on par in its demand upon gullibility as divine revelation.