Prabhupada: Ceto-darpana-marjanam [Cc. Antya 20.12]. And then bhava-maha-davagni… Then his material pangs will be over. This is the only medicine. Therefore chant Hare Krsna. Some way or other, let them have the chance of hearing, and then it will act as medicine
If we hear properly, the holy name will enter through our ears into the region of our heart and shower down nectar. When we are lost in the ocean of nectar, we will see Krishna.
Living beings who are entangled in the complicated meshes of birth and death can be freed immediately by even unconsciously chanting the holy name of Krishna, which is feared by fear personified. — Srimad Bhagavatam, 01.01.15.
Terrorist guns can kill the material body, but the Holy Name of the Lord can kill the enemies within the mind of the person.