Great Lent before Easter is when the Christian participates fully in preparing himself to praise and glorify his God as Lord and Savior. Great Lent is like a "workshop" where the character of the faithful is spiritually uplifted and strengthened; where his life is rededicated to the principles and ideals of the Gospel; where the faith culminates in deep conviction of life; where apathy and disinterest turn into vigorous activities of faith and good works. Lent is not for the sake of Lent itself, as fasting is not for the sake of fasting. But they are means by which and for which the individual believer prepares himself to reach for, accept and attain the calling of his Savior. Therefore, the significance of Great Lent is highly appraised, not only by the monks who gradually increased the length of time of the Lent, but also by the lay people themselves, although they do not observe the full length of time. As such, Great Lent is the sacred Institute of the Church to serve the individual believer in participating as a member of the Mystical Body of Christ, and, from time to time, to improve the standards of faith and morals in his Christian life. The deep intent of the believer during the Great Lent is "forgetting what lies behind and straining forward to what lies ahead, I press on toward the goal of the prize of the upward call of God in Christ Jesus", Philippians 3:13-14.
Great Lent, or the Great Fast, (Greek: Μεγάλη Τεσσαρακοστή or Μεγάλη Νηστεία, meaning "Great 40 Days," and "Great Fast," respectively) is the most important fasting season in the church year in Orthodox Christianity including Western Rite Orthodoxy, which prepares Christians for the greatest feast of the church year, Pascha (Easter).
Source: Greek Orthodox Archdiocese of America, http://www.goarch.org/ourfaith/ourfaith8126.