Srimad Bhagavatam Canto 11, Chapter 23, Text 22

SB 11.23.22

labdhva janmamara-prarthyam
 manusyam tad dvijagryatam
tad anadrtya ye svartham
 ghnanti yanty asubham gatim
Those who obtain human life, which is prayed for even by the demigods, and in that human birth become situated as first-class brahmanas, are extremely fortunate. If they disregard this important opportunity, they are certainly killing their own self-interest and thus achieve a most unfortunate end.
Srila Bhaktisiddhanta Sarasvati Thakura comments as follows. “Human birth is better than that of the demigods, ghosts, spirits, animals, trees, lifeless stones, and so forth, because the demigods simply enjoy celestial pleasures, and in other forms of life there is excessive suffering. It is only in human life that one deeply considers one’s ultimate benefit in life. Human birth is therefore more desirable than even that of the demigods.” Within human life the position of a high-class brahmana is certainly most desirable. If a brahmana, however, gives up the devotional service of the Lord and works hard like a sudra simply for the prestige of his community, he is certainly on the platform of material sense gratification. The special qualification of the brahmanas is the spiritual knowledge by which they recognize every living entity to be an eternal servant of the Lord. A brahmana, free from false ego, thus feels himself lower than a blade of grass and tolerantly offers respect to all living entities. All human beings, and especially the brahmanas, should avoid becoming killers of their own self-interest by neglecting Krsna consciousness, the loving service of the Lord. Such neglect paves the way for future suffering.
Srimad Bhagavatam Canto 11, Chapter 23, Text 21
Srimad Bhagavatam Canto 11, Chapter 23, Text 23