Krishna's Body is Spiritual

Krishna is non-different from His body. His body is eternal, full of bliss, and knowledge.1 He never changes His body, hit in His self-same body appears in different ways, according to His desires, in His various incarnations.2 This is the same as a dramatic artist who can expertly assume different roles according to the scripts which he is called upon to perform. It is stated in the Vedic literatures, that when we see God in His original manifestation, He is known as Krishna - the all attractive Personality of Godhead. In His various manifestations in this world, Krishna establishes religious principles, annihilates miscreants, and helps His devotees.2 At the same time, He exhibits these activities to attract people who have no information about God other than their faulty speculation or the speculations of others such as theologians. When people see or hear about Krishna's wonderful activities, they become attracted to him, and become interested in spiritual life.

Krishna also enjoys acting in many different ways. God is not impersonal. He has desires like ourselves, but His desires are not fraught with the impurities that contaminate ours. He enjoys dancing, playing, singing, fighting, and all the activities that we can imagine.

In the spiritual world these activities are constantly going on. This is the destination of the pure devotees of the Lord:
To interact with the Lord in His eternal pastimes.
1. Brahma-samhita 5.1
2. Bhagavad.gita 4.6