More important than physical purification is inner purification. How do you practice this? Watch what you think, feel and say. This is the essence. What comes out of the mouth is more important than what goes in. If you eat something dirty, the body gets dirty. But remember that you are not the body. If what comes out of the mind or the mouth is dirty, it dirties the incarnated soul. There is no point in eating clean food if what comes out of the mouth is dirty. You have to speak courteously. You cannot dirty somebody without dirtying yourself. Is it worth saying or thinking bad things over and over again, and in the process letting your incarnated soul wallow in the mud?
As you purify yourself thoroughly, your incarnated soul will be able to function on a higher level of consciousness until it can unite with your higher soul.
One time, a student was given a Shaktipat or Spiritual Empowerment. Her consciousness was going higher and higher for a while, but then it started to go down. What was the reason for this? The “weight of inner impurities” was pulling her consciousness down. You, the incarnated soul, are like a balloon. Throw away the weights of impurities and you will be able to fly upwards. You will become spiritually lighter. The higher soul is pure, while the incarnated soul has wallowed in mud. Character-building is very important because it is a way to purify the incarnated soul. As you privy yourself thoroughly, your incarnated soul will be able to function on a higher level of consciousness until it can unite with your higher soul.
Reference : Achieving Oneness with the Higher Soul. Master Choa Kok Sui.