peace

a person whose mind and wisdom is not controlled cannot have the wisdom of being stable in only God. as a result he fails to achieve peace and happiness.

This shloka of geeta says:

A person whose mind and senses are not controlled can not have the fixed, only target of achieving God. because his uncontrolled mind and senses keep him dragging back to material world again and again.

He can never realize the golden truth that I have to do only my duties, without getting addicted to the results thereof. His senses and mind veer toward addiction.

As he is driven by his senses he fails to become dufiful. As a result of that he fails fulfill his duties with conviction and strength, and finally he fails to achieve peace.

A person without peace cant be happy. No matter how much he derives in material world his hunger increases. His heart is always restless and unsatisfied. So he fails to be peaceful and happy.