Holiness is a commandment that must be pursued and kept by all believers because it is not granted by Jesus or by His blood and cannot be dismissed because, as Satan claims and teaches, men can never become holy. 

Yehoshua (Jesus) Messiah YHWH is holy.

According to Leviticus 20:7-8, Jesus says we must be holy because the Godhead is holy. Leviticus 20:7-8, 1 Peter 1:15-16, Numbers 15:40, Romans 12:1-2, et cetera, do not hint to a passive role of man to become holy, counting on the holiness of the Jesus to render us holy. We must actively work out our salvation with fear and trembling (Philippians 2:12) to overcome to become holy (Revelation 3:20-21) because we will not see the face of Jehovah without being holy (Hebrews 12:14). It makes sense when we understand that sin is a disagreement with God and that it is illogical that the Godhead will take in men who disagree with God.

Hebrews 12:14 ASV

(14) Follow after peace with all men, and the sanctification [holiness) without which no man shall see the Lord:

Romans 12:1-2 ASV

(1) I beseech you therefore, brethren, by the mercies of God, to present your bodies a living sacrifice, holy, acceptable to God, which is your spiritual service.

(2) And be not fashioned according to this world: but be ye transformed by the renewing of your mind, that ye may prove what is the good and acceptable and perfect will of God.

Leviticus 20:7-8 ASV

(7) Sanctify yourselves therefore, and be ye holy; for I am Jehovah your God.

(8) And ye shall keep my statutes, and do them: I am Jehovah who sanctifieth you.