Indoctrinate implies the recipient is not encouraged to question what they learn. The cult's leader sought to indoctrinate members by discouraging any doubts.
Pro Tip 2/3
Not Just Negative
While often negative, 'indoctrinate' can be neutral, relating to firm beliefs instilled. Her parents sought to indoctrinate a sense of morality and kindness in her.
Pro Tip 3/3
Strong Influence
Indoctrination usually involves strong influence and can last for a long time. He was indoctrinated into the ideology from a young age.