The word in the Bible for "saint" or "saints" is the word (hagios) also translated "sanctified" or "holy ones." The root word hazo, means "to venerate." Hagios means to be separated from sin and therefore consecrated to God.
Hagios is used of God (Lk 1:49; Acts 3:14; Mt 1:18, etc.). It is a word used of men and things (1 Tim 1:9; 1 Pet 2:5,9, etc.)
When Paul uses the word "saint" in the singular, he refers to a state into which God calls men with His grace. Phil 4:21 Give my greetings to every holy one (hagion) in Christ Jesus.
In its plural form, Paul uses the word to refer to all believers. For Paul, the word is not applied only to persons of exceptional holiness, nor to those having died characterized by an exceptional life of saintliness.
Eph 2:19 So then you are no longer strangers and sojourners, but you are fellow citizens with the holy ones (hagios) and members of the household of God,
Rom 12:13 Contribute to the needs of the holy ones, exercise hospitality.
Rom 16:15 Greet Philologus, ... and all the holy ones who are with them. 1
Cor 16:1 Now in regard to the collection for the holy ones, you also should do as I ordered the churches of Galatia.
1 Cor 16:15 I urge you, brothers--you know that the household of Stephanas is the firstfruits of Achaia and that they have devoted themselves to the service of the holy ones--
It is Paul who calls all his fellow believers "saints," and not just the notably holy ones. Paul also uses the term for both those who are living and for those who are dead.
2 Thess 1:9-10 These (who do not acknowledge God nor heed the good news) will pay the penalty of eternal ruin, separated from the presence of the Lord and from the glory of his power, when he comes to be glorified among his holy ones (hagiois) and to be marveled at on that day among all who have believed, for our testimony to you was believed.
Jude 14-15 Enoch, of the seventh generation from Adam, prophesied also about them when he said, "Behold, the Lord has come with his countless holy ones (hagiais) to execute judgment on all and to convict everyone for all the godless deeds that they committed ..."
This practice of Paul corresponds to one of the earliest creedal statements of Christian faith: The Apostles Creed: "I believe in the communion of saints." Communion of saints refers to the bond of unity among all believers, both living and dead, who are or have been committed followers of Jesus Christ. In the eyes of God, in eternity, the distinction between His People who are "living" or who are "dead" is not at all important.
Mk 9:4 Then Elijah appeared to them along with Moses, and they were conversing with Jesus.
Mk 12:26-27 "As for the dead being raised, have you not read in the Book of Moses, in the passage about the bush, how God told him, 'I am the God of Abraham, (the) God of Isaac, and (the) God of Jacob'? He is not God of the dead but of the living. You are greatly misled."
Lk 23:43 He replied to him (the crucified thief) "Amen, I say to you, today you will be with me in Paradise."
Rom 12:5 ... so we, though many, are one body in Christ and individually parts of one another.
The saints are presented to believers as role models whose lives are worthy to be imitated.
Heb 6:12 ... so that you may not become sluggish, but imitators of those who, through faith and patience, are inheriting the promises.
Heb 12:1 Therefore, since we are surrounded by so great a cloud of witnesses, let us rid ourselves of every burden and sin that clings to us and persevere in running the race that lies before us
1 Cor 11:1 Be imitators of me, as I am of Christ.
Phil 3:17 Join with others in being imitators of me, brothers, and observe those who thus conduct themselves according to the model you have in us.