The Enchanted Wanderer: Ocharovannyy strannik

The protagonist, Ivan Flyagin, a bogatyr-type of a character has been "promised to God" by his mother but refused to join the monastery as a young man, ignoring all the "signs", allegedly pointing him the way. The rest of his life he sees as a "punishment" for this, and after all becomes a monk, driven though not by spiritual motives, but rather by poverty and having nowhere else to go.