Ex 31:13, Lev 20:8, Lev 21:5, Lev 22:9,16,32
God promised in the Old Testament that if we keep His commandments, He will sanctify us. (Ex 31:13, Lev 20:8, Lev 22:9,32)
Ex 31:13 Speak thou also unto the children of Israel, saying, Verily my sabbaths ye shall keep: for it is a sign between me and you throughout your generations; that ye may know that I am the Lord that doth sanctify you.
Lev 20:8 And ye shall keep my statutes, and do them: I am the Lord which sanctify you.
Lev 22:9 They shall therefore keep mine ordinance, lest they bear sin for it, and die therefore, if they profane it: I the Lord do sanctify them. 32 Neither shall ye profane my holy name; but I will be hallowed among the children of Israel: I am the Lord which hallow you,
God sanctified us by sacrificing Jesus for us. (Heb 2:11)
Heb 2:11 For both he that sanctifieth and they who are sanctified are all of one: for which cause he is not ashamed to call them brethren,