You can sense a lot of emotions and feelings in your life. Happiness, Sorrow, Anger, Hatred, Love, etc. But peace of mind and satisfaction are the most evasive feelings or emotions in life. They are very hard or rather seems very hard to find and sense.
In short, you can acquire a lot of feelings or emotions like those mentioned above through evil or bad means. But you cannot get peace of mind or satisfaction through those means. You need some serene way to acquire such divine emotion.
Yoga gives you that ever evasive feeling or sensation of satisfaction or peace of mind. (So Yoga is not some sin. Its the most amazing means to get moksha or rather reach the almighty)
Go through the posts below. It will help you to get some idea.
Yoga is attaining balance of mind, body and spirit.
Wish you all the best...