Sri Krishn does not need our service, but He kindly accepts it. When Sri Krishn asks us to surrender unto Him (Sarva-dharmaan parityajya maam ekam saranam vraja), this does not mean that Sri Krishn is lacking servants and that if we surrender He will profit. Sri Krishn can create millions of servants by His mere desire. So that is not the point. But, if we surrender to Sri Krishn, we shall be saved, for Sri Krishn says ‘aham tvaam sarva paapebhyo moksayisyami : ‘I shall free you from all sinful reactions’.