When a person has concentration, but no mental purity, he or she can obtain great powers. But without purity of mind and nobility of thoughts that power will only be used for the destruction of himself and others.
All the scientific discoveries of the modern age, instead of helping to make our lives more happy and wonderful, are now becoming a curse for us, because science has fallen into the hands of people with perverted and crooked minds.
Consequently, although our life has become much more comfortable, there is still so much fear and insecurity not knowing when and where someone will blast a nuclear bomb.
Fear will continue to exist as long as our minds remain impure, for the money, power and other sources of strength that we acquire will be utilized for our own destruction.
(Source – Vibhishana Geeta by Swami Tejomayananda)