Hindus believe that human civilization degenerates spiritually during the Kali Yuga, which is referred to as the Dark Age because in it people are as far away as possible from God.
Prophesied events during a Kali Yuga
‣Rulers will become unreasonable: they will levy taxes unfairly.
‣Rulers will no longer see it as their duty to promote spirituality, or to protect their subjects: they will become a danger to the world.
‣People will start migrating, seeking countries where wheat and barley form the staple food source.
With regard to human relationships, Markandeya's discourse says:
‣Avarice and wrath will be common. Humans will openly display animosity towards each other. Ignorance of dharma will occur.
‣People will have thoughts of murder with no justification and will see nothing wrong in that.
‣Lust will be viewed as socially acceptable and sexual intercourse will be seen as the central requirement of life.
‣Sin will increase exponentially, while virtue will fade and cease to flourish.
‣People will take vows and break them soon after.
‣People will become addicted to intoxicating drinks and drugs.
‣Gurus will no longer be respected and their students will attempt to injure them. Their teachings will be insulted, and followers of Kama will wrest control of the mind from all human beings.
‣Brahmans will not be learned or honored, Kshatriyas will not be brave, Vaishyas will not be just in their dealings.