Holiness is the complete setting apart of a thing for one particular purpose.
Holiness is a way of life dedicated to God.
A saint is one who lives without sin, according to the will of God.
“For the death that He died, He died to sin once for all; but the life that He lives, He lives to God. Likewise you also, reckon yourselves to be dead indeed to sin, but alive to God in Christ Jesus our Lord. Therefore do not let sin reign in your mortal body, that you should obey it in its lusts. And do not present your members as instruments of unrighteousness to sin, but present yourselves to God as being alive from the dead, and your members as instruments of righteousness to God. <...> And having been set free from sin, you became slaves of righteousness. <...> But now having been set free from sin, and having become slaves of God, you have your fruit to holiness, and the end, everlasting life” (Rom. 6:10-13,18,22)
“Whoever has been born of God does not sin, for His seed remains in him; and he cannot sin, because he has been born of God” (1 John. 3:9)
“We know that whoever is born of God does not sin; but he who has been born of God keeps himself, and the wicked one does not touch him” (1 John. 5:18)
“Pursue peace with all people, and holiness, without which no one will see the Lord” (Heb. 12:14)
“The city had no need of the sun or of the moon to shine in it <...> Its gates shall not be shut at all by day (there shall be no night there). <...> But there shall by no means enter it anything that defiles, or causes an abomination or a lie, but only those who are written in the Lamb’s Book of Life” (Rev. 21:23,25,27)