Detail of an 11th-century fresco of Basil the Great celebrating the Mass
Meister der Sophien-Kathedrale von Ohrid
He was a famous preacher, and many of his homilies, including a series of Lenten lectures on the Hexaëmeron (the Six Days of Creation), and an exposition of the psalter, have been preserved. Some, like that against usury and that on the famine in 368, are valuable for the history of morals; others illustrate the honor paid to martyrs and relics; the address to young men on the study of classical literature shows that Basil was lastingly influenced by his own education, which taught him to appreciate the propaedeutic importance of the classics.
In his exegesis Basil was a great admirer of Origen and the need for the spiritual interpretation of Scripture. In his work on the Holy Spirit, he asserts that "to take the literal sense and stop there, is to have the heart covered by the veil of Jewish literalism. Lamps are useless when the sun is shining."
Side Note: In Greek tradition, he brings gifts to children every January 1 (St Basil's Day) — unlike other traditions where Father Christmas arrives either on December 6 (Saint Nicholas Day) or on Christmas Eve (December 24). It is traditional on St Basil's Day to serve vasilopita, a rich bread baked with a coin inside. It is customary on his feast day to visit the homes of friends and relatives, to sing New Year's carols, and to set an extra place at the table for Saint Basil. Basil, being born into a wealthy family, gave away all his possessions to the poor, the underprivileged, those in need, and children. A similar story exists for another Greek bishop, Saint Nicholas of Myra. Over the centuries the two legends have blended together, though the Western Santa Claus remains associated with Nicholas, while the Eastern "Santa" is identified with Basil.
Saint Basil died on January 1, and the Eastern Orthodox Church celebrates his feast day together with that of the Feast of the Circumcision on that day. This was also the day on which the Roman Catholic calendar of saints celebrated it at first; but in the 13th century it was moved to June 14, a date believed to be that of his ordination as bishop, and it remained on that date until the 1969 revision of the calendar, which moved it to January 2, rather than January 1, because the latter date is occupied by the Solemnity of Mary, Mother of God. On January 2 Saint Basil is celebrated together with Saint Gregory Nazianzen. Some traditionalist Catholics continue to observe pre-1970 calendars.
Basil's entire Wikipedia entry is at: http://en.wikipedia.org/wiki/Basil_of_Caesarea