If we allow everything access to our mind, we are simply asking to be kept in a state of mental turmoil or bondage. For nothing enters the mind without having an effect for good or evil.
Crooked thinking, unintentional or not, always favors evil.
The needed transformation is very largely a matter of replacing in ourselves those idea systems of evil (and their corresponding cultures) with the idea system that Jesus Christ embodied and taught and with a culture of the kingdom of God.