Monastic Obedience and Discernment
Longinus made his monastic obedience at the Kiev Caves monastery, serving as the community's gatekeeper. The synaxarion records that his prayerful fervor and humble love for work were rewarded by the Lord with the gift of discernment.
In the role of gatesman he stood at the threshold between the world and the monastery. The synaxarion relates that he encouraged people who came to the Lavra with good intent, while he denounced those inclined to wickedness and urged them to repentance — an exercise of the discernment attributed to him.