Devotion through surrender.

The aspirant who does not have a feeling of egoism, who has completely surrendered himself, his deeds, and the fruits of his actions to his single goal, the supreme Lord, is not considered to be an evil doer even if he kills someone in the battlefield, because he has profound knowledge of life, love, and equality, and his actions are completely dedicated to the Lord. He is free from the I-ness of his ego and is a representative of the Lord. He has no intention to injure, hurt, harm, or kill anyone. Swami Rama, Perennial Psychology of the Bhagavad Gita, Pp. 436.