A Saint (Heb: קָדוֹשׁ; Gr. ἅγιος) is a person set apart by God to be special to Him. It is used of of priests and others in God's service in the Old Testament. A similar fashion, all true believers within the Church are called saints.
Holiness of the Believer
See Main article: Holiness
Holiness is one of the main attributes of God, for it points to His complete separateness from His creation and creatures. However, in both the Old and New Testaments, it is emphasized that it is necessary for His people to be "holy" in a way that is humanly impossible.