[Cronos]

All historical documents state that Ambrose was raised in a Christian family and was Christian not pagan. If you read “he was baptised as an adult” and assume that that means he was a pagan until an adult, that is flawed, personal interpretation, sola scriptura, sola interpretura. Just like the flawed personal interpretation of the bible

[xone]

All historical documents state that Ambrose was raised in a Christian family

There is reason to doubt the 'Christianity' if there is no proof. Isn't that a Catholic outlook on a faith without works? Why no baptism if in a practicing Christian household? I think the assumption of non-believer is substantiated barring some other plausible reason for not being baptized.

Just like the flawed personal interpretation of the bible

You aren't equating the written history of St Ambrose's life to reading the Bible, are you. And if the Holy Spirit is guiding ones reading, it it really a 'personal' interpretation any longer?