According to Hinduism, we are living in the last yuga called Kaliyuga. There are four time zones called as yugas which are: Satya yuga, Treta yuga, Dwapara yuga and Kaliyuga. It is believed that at the end of Kali yuga the world will seize to exist. These four yugas are like kalachakra (wheel of time), which keep rotating without beginning and end.
As we walkthrough these different yugas, there is a pattern in which evil grows stronger. Where there is good, there is also evil. Good has no value if evil does not exist. Let's analyse each yugas one after the other:
Satya Yuga: In this era humanity was at its best. There was not an ounce of evil on earth. The evil in the form of daemon was contained in a separate world. It was as if good and evil were world's apart. Dharma was reigning throughout the earth and there was no chance for Adharma to make way inside.
Treta Yuga: This time zone saw the greatest king to ever rule the earth and he is none other than The Lord Rama. He is the personification of Dharma. He is the protagonist of the epic Ramayana which is based on his life. Ravana an outsider who wants to control the entire world through his evil means comes from daemon world to earth. This showed evil was slowly creeping in from outside.
Dwapara Yuga: Another great epic Mahabharata took place during this era. It witnessed the first ever Dharma yuddha(war) called kurukshetra. The magnitude of this war was so big that it wiped out half the population from the face of the earth. A family feud between brothers over kingdom and power caused such a deathly war. This showed evil was making way inside family.
Kali Yuga: This era is probably considered the worst of all yugas. As you see day by day humanity is lost. Adharma is increasing gradually. The evil is not outside anymore, it has reached inside us. There is a saying that we all have two kinds of dog inside us, one good dog and another evil dog. Your character is built upon the kind of dog you feed and nurture more.
Let's pledge to save humanity and try to make better versions of ourselves day by day. This is the only way to escape from the crutches of evil and leave behind this world with good karma to carry forward for next life.