In the dark age (Kali yuga)
(Golden age) demigods and demons lived on different planets. In the next Treta yuga they where living on one planet. In the next third Dvapara yuga they lived in one family together. And in the Kali yuga (Dark age) we are in now, they live in one body. This means that in Kali yuga we all have divine and demonic nature within us, someone has more or less of one or the other. And in order to kill our own demons within us, one must choose "Spiritual" Consciousness and association with the devotees. This is a way to receive a mercy, because in this Kali yuga we are so weak that it is not possible in this yuga to attain self-realization and purification by ourselves.
We simply need mercy to have success in our spiritual elevation and to be able to progress in our spiritual life.
Jut like “One stick is easy to break but when there are 1000 of them it is impossible.”