His Grace Bishop Longin of New Gračanica and Midwest America was born on September 29, 1955 as Momir Krčo in the town of Kruscanje Olovo. His parents were Stanoje and Andja Jovanovic. He attended grade school in Olovske Luke from 1962 to 1970. He entered Three Hierarchs Seminary in Monastery Krka in 1970 and graduated in 1975.
During this time he was tonsured a monk and received the small schema as a fifth year student. The tonsuring was done by Bishop Stefan of Dalmatia on the eve of the school Slava of the Holy Three Hierarchs on February 11, 1975. At the Divine Liturgy on February 12th he was ordained a deacon by Bishop Stefan. On February 13th, he was ordained a priest (he was twenty years old at time of his priestly ordination.)
He entered the Moscow Theological Academy in 1975 where he graduated in 1979. From October 1980 to April 1981, he served in the Diocese of Zvornik-Tuzla as secretary of the Executive Board. He was also administrator of two parishes. On the decision of the Holy Synod of Bishops he was appointed as lecturer of the Holy Three Hierarchs Seminary in 1983 for two years.