There are several Hebrew words for holiness in the Tanakh/Old Testament. For the scriptures below, qodesh and qadowsh are used. Qodesh
{ko'-desh} means a sacred place or thing; sanctity:--consecrated (thing), dedicated (thing), hallowed (thing), holiness, holy, saint, sanctuary. Qadowsh
{kaw-doshe'} or qadosh {kaw-doshe'}; means sacred (ceremonially or morally); (as noun) God (by eminence), an angel, a saint, a sanctuary:--holy (One), saint. From the New Testament we will be using hagios
{hag'-ee-os} which means sacred (physically, pure, morally blameless or religious, ceremonially, consecrated):--(most) holy (one, thing), saint. Another definition is hagiasmos
{hag-ee-as-mos}. It means properly, purification:--holiness, sanctification. Holiness is being set apart for the glory and will of God. To be holy is one of the essential elements of God's requirements to those He has called.
Isaiah 62:12 And they shall call them, The holy people, The redeemed of the LORD: and you will be called, Sought out, A city not forsaken.
Romans 12:1-2 as well as Ephesians 1:3-4
1 Thessalonians 4:7:For God hath not called us unto uncleanness, but unto holiness.
1 Peter 1:15-16
Revelation 22:11: He that is unjust, let him be unjust still: and he which is filthy, let him be filthy still: and he that is righteous, let him be righteous still: and he that is holy, let him be holy still.