Joasia,
Saint John of Kronstadt was, in life, a married priest and not a bishop. Kronstadt was a naval port and he lived very much in the world while not being of it. The area around his church would have been colourful and all of mankind's sins only too obvious with drunkards, thieves, prostitutes and rapacious landlords among others in all too evident abundance. To be a priest in this environment would have been a challenge for any, and for someone as wholehearted in his pastoral care as Saint John a cross beyond imagination.
Any who think to escape to some kind oasis of 'spiritual peace' in a convent or monastery are in for a rude awakening, I suspect, because convents and monasteries are populated by people. (I can sense my cousin nodding vigorously).
As to the comment by another that the lives of Saints were added to, I suspect that much was left out being known only to that ascetic struggler and Our Merciful God. Just as we see the feats of athletes on the field but not all the training and sacrifice which lead up to that performance on the day. (Even the protestant reformer John Calvin was fullsome in his praise and recognition of the truly ascetic struggle and lifestyle of the early desert fathers - should we be less will to recognise the struggle of others?).