We have innumerable shining examples of the repentance of people, who were far from God, who then returned and were not merely saved, but reached great measures of holiness.
What was Venerable Mary of Egypt? How many were there who like Venerable Mary had been sinful people, who then became saints afterwards! That is why no one should despair, but come with repentance to their spiritual father, who with his word can make the sinner reconcile with God, who can justify him instantly. "Whatever you loose on earth, will be loosed in heaven. The grace of the All-Holy Spirit has forgiven you and loosed you both in the present age and in the future." Automatically in God's "computer" there are zero sins and at the same time the gate of the Kingdom of Heaven opens. The Bridal-Chamber of Christ accepts the human being, the one who previously did not have the soul's garment made bright.
For this great compassion of God, let us thank Him, let us venerate Him with all the gratitude of our souls. If God were not so infinitely compassionate, none would be saved.
From The Art of Salvation. Translation by John Sanidopoulos.