atmaiva hy atmano bandhur
atmaiva ripur atmanah
Meaning: One must deliver himself with the help of his mind, and not degrade himself. The mind is the friend of the conditioned soul, and his enemy as well.
For man, mind is the cause of bondage and mind is the cause of liberation. Mind absorbed in sense objects is the cause of bondage, and mind detached from the sense objects is the cause of liberation.
Bhagavad Gita: Mind always engaged in divine consciousness is the cause of supreme liberation. (Dhyana-yoga (Text 05, Ch 6))