The unsuccessful yogi, after many, many years of enjoyment on the planets of the pious living entities, is born into a family of righteous people, or into a family of rich aristocracy. (Bg. 6.41) Some devotees, having failed to complete the process of devotional service, are promoted to the heavenly planets, to which the pious are elevated, and after enjoying there they may be directly promoted to the place where the Lords pastimes are going on. When Lord Krsna was to appear, the denizens of the heavenly planets were invited to see the pastimes of the Lord, and thus it is stated here that the members of the Yadu and Vrsni dynasties and the inhabitants of Vrndavana were demigods or almost as good as demigods. Even those who externally helped the activities of Kamsa belonged to the higher planetary systems. The imprisonment and release of Vasudeva and the killing of various demons were all manifestations of the pastimes of the Lord, and because the devotees would be pleased to see these activities personally, they were all invited to take birth as friends and relatives of these families. As confirmed in the prayers of Kunti (Bhag. 1.8.19), nato natya-dharo yatha. The Lord was to play the part of a demon-killer, and a friend, son and brother to His devotees, and thus these devotees were all summoned.