This is a quotation from Srimad-Bhagavatam (11.29.34). At the time of initiation, a devotee gives up all his material conceptions. Therefore, being in touch with the Supreme Personality of Godhead, he is situated on the transcendental platform. Thus having attained knowledge and the spiritual platform, he always engages in the service of the spiritual body of Krsna. When one is freed from material connections in this way, his body immediately becomes spiritual, and Krsna accepts His service. However, Krsna does not accept anything from a person with a material conception of life. When a devotee no longer has any desire for material sense gratification, in his spiritual identity he engages in the service of the Lord, for his dormant spiritual consciousness awakens. This awakening of spiritual consciousness makes his body spiritual, and thus he becomes fit to render service to the Lord. Karmis may consider the body of a devotee material, but factually it is not, for a devotee has no conception of material enjoyment. If one thinks that the body of a pure devotee is material, he is an offender, for that is a vaisnava-aparadha. In this connection one should consult Srila Sanatana Gosvami's Brhad-bhagavatamrta (1.3.45 and 2.3.139).