I think you do need to attack Biblical Literalism, but to be successful, that needs to be done from within the Christian communion.
It will not work if the attack comes from someone who does not accept the Bible as a Holy Book, and may not work even if the attacker accepts the Bible as a Holy Book , but that is IMHO the only possible way it might succeed.
The approach needs to be multipronged, and I don't think there is any one most convincing evidence. rather it is the overwhelming weight of ALL of the evidence that is compelling.
Aslan is not a
Tame Lion