The "saints" are those who do God's will, most of whom have given up any and all
aspects of their lives that do not serve God.
The Old Testament Prophets cn be considered saints, so can the Apostles and Martyrs of the Bible.
In the Roman Catholic and Eastern Orthodox traditions, the Saints are those persons who have through
their faith and works have shown that they have a very close and personal relationship with God and for the most part
have been formally recognized by the Church.
St. Francis of Assissi or St. John Chrysostom would be good examples.
There are several living Saints on Mount Athos, I know of one in Arizona, Elder Ephraim of Philotheou.
"Saints" are holy ones. In the Bible, three different words are used. One word, used only in the Old Testament (Hebrew chacidh), means good or righteous (ex. 1 Samuel 2:9). The other two words (Hebrew qadhosh and Greek hagioi) mean holy, consecrated (set apart) to God (ex. Deuteronomy 33:3, Acts 9:13, Romans 1:7). This second sense is not about the character of the person, but about his or her relationship to God. Only God can put someone into this relationship.
Paul called the Corinthian believers saints in 1 Corinthians 1:2 (the words 'to be' are not present in the original languages). This is significant, because by any moral standard, they were not qualified to be called saints. They were divisive and sexually immoral. Yet, Paul called them saints because they were "sanctified in Christ Jesus".
Of course, Paul exhorted them to live up to their calling - that was the purpose of his letter. But positionally, they were already holy, even in their carnal condition.