When grace is operative in the soul of someone who is praying, then he is flooded with the love of God, so that he can no longer bear what he experiences.
Afterwards, this love turns towards the world and man, whom he comes to love so much that he seeks to take upon himself the whole of human pain and misfortune so that everyone else might be freed from it. In general he suffers with every grief and misery, and even for animals, so that he weeps when he thinks they are suffering.
These are the properties of love, but it is prayer that activates them and calls them forth.
This is why those who are advanced in prayer do not cease to pray for the world. To them belongs even the continuation of life, however audacious and strange this may seem. And you should know that, if such people disappear, then the end of this world will come.
- Elder Joseph the Hesychast