‘Anyone who teaches that all are good, he will bring about the end of the world.’ ‘The one who taught that was crucified.’ ‘He will come, and his name will be Man-God.’ ‘God-Man?’ 20 ‘Man-God, there’s a difference.’
Stavrogin is thinking of Christ. Man-god is the reverse of Christ. Kirillov isn't referring to the end-times where all the earth will be renewed - he's thinking of death.