Question: Why is the Heavenly Demon (天魔) King (魔王) Māra (魔罗) present in our world-system (世界)?
Answer: As this is a defiled land (秽土), this world thus has Māra, who is simply the most powerfully evil (恶) being, although any Māra is never more powerful than any Buddha. Due to great pride and stubbornness despite being defeated repeatedly, Māra refuses to heed the Buddhas’ teachings at the moment.
Despite being very evil with much of the Three Poisons (三毒) of greed, hatred and delusion (贪嗔痴), Māra is also able to have much power due to much past good karmas (善业), which he abuse. Of course, since he is actively doing evil now, those good karmas will exhaust, while his evil karmas (恶业) increase.
‘Māra’ is however, not a fixed being; more like a position. When the present one karmically falls to a lower realm later, the next most ‘Māra-ish’ being will fill the position, taking over the ‘power vacuum’. Again, due to this being a defiled land with our collective karmas (共业) and ‘his’ distinct karmas (别业), Māra’s presence persists.
The only way for there to be no more Māras is when there are no more beings creating Māra-ish karmas, with no more beings karmically deserving disturbances of such a being too, by becoming good and purified adequately. Note that Māras’ presence is not due to the existence of any creator, but the creating of great evils.
