Without mind you cannot think of
God, without it you cannot concentrate and meditate. Without mind and emotions, thoughts and feelings, you cannot have Bhava
and Bhakti.
Therefore, the mind is a necessary instrument, and at the same time
if it is not properly understood and managed, it becomes your own undoer.
Therefore
it is a necessary evil, which has to be turned into an aid. To turn the impure
mind into pure mind is no less a part of Yoga than Kirtan, Japa and the like.
Every aspirant has to use his intelligence and manage the important task of
ruling the senses and the mind. You can manage an unruly thing, only if you
understand it. Unless he who drives the horse, knows its habits, he cannot
manage it. Therefore, this is a very important part of Sadhana.
"For one who has conquered the mind, this is his best friend; but for one who has not, the mind will remain his greatest enemy." ~ Bhagavad Gita. - Cap. 6.6