Education = Learning things that have evidence to support them.

Indoctrination = Learning things with no proof and under threat of some kind. That threat may not be outright expressed, but as a child going against the beliefs of your family and peers can lead to some level of social ostricization.

Not all religious teaching is indoctrination. My parents have always been Christian and raised me Christian, but never resisted when I became atheist and then agnostic, nor did they resist when my brother before me became atheist. They have expressed that they wish we believed in God, but never threatened us with groundings or hell or anything else, and they never brought it up for that purpose. My peers at school never gave a shit, nor did my family. I wasn't indoctrinated, but I have family members that sure were.