You want pedantic? Let’s get pedantic.
John may not consider himself a theist, but John is still pro-theism. Theism is not an action, though.
If John is anti-anti-murder, then John is pro-murder.
If John is anti-anti-rape, then John is pro-rape.
If John is anti-anti-torture, then John is pro-torture.
John actively opposes opposition to evil. John is a willing accomplice.
See how that works?