Is it OK, while we pray, to cover ourselves with the blood of Jesus? For example, we cover ourselves with the blood of Jesus for protection. You remember the Passover when a lamb's blood was used for protection against death? In that same way, a better blood that speaks more than that of a lamb can be used as a means of protection when we declare and believe it with faith, isn't it?
It is interesting how people take phrases from the Bible and combine them to create something that the Bible never teaches. I can find no passage that talks about the blood of Jesus covering anything. There are numerous passages that speak of Christ's blood cleansing us, but that is a different concept.
"If we say that we have fellowship with Him and yet walk in the darkness, we lie and do not practice the truth; but if we walk in the Light as He Himself is in the Light, we have fellowship with one another, and the blood of Jesus His Son cleanses us from all sin. If we say that we have no sin, we are deceiving ourselves and the truth is not in us. If we confess our sins, He is faithful and righteous to forgive us our sins and to cleanse us from all unrighteousness" (I John 1:6-9).
"For this is My blood of the covenant, which is poured out for many for forgiveness of sins" (Matthew 26:28).
"Much more then, having now been justified by His blood, we shall be saved from the wrath of God through Him" (Romans 5:9).
"In Him we have redemption through His blood, the forgiveness of our trespasses, according to the riches of His grace" (Ephesians 1:7).
"For if the blood of goats and bulls and the ashes of a heifer sprinkling those who have been defiled sanctify for the cleansing of the flesh, how much more will the blood of Christ, who through the eternal Spirit offered Himself without blemish to God, cleanse your conscience from dead works to serve the living God?" (Hebrews 9:13-14).
"Knowing that you were not redeemed with perishable things like silver or gold from your futile way of life inherited from your forefathers, but with precious blood, as of a lamb unblemished and spotless, the blood of Christ" (I Peter 1:18-19).
"To Him who loves us and released us from our sins by His blood" (Revelation 1:5).
"These are the ones who come out of the great tribulation, and they have washed their robes and made them white in the blood of the Lamb" (Revelation 7:14).
The concept of Jesus being the Passover Lamb is true, but again it applies to the removal of sin. "The next day he saw Jesus coming to him and said, "Behold, the Lamb of God who takes away the sin of the world!"" (John 1:29). The blood on the doorposts was to have the death angel to pass over the home, so you can say the occupants were protected from death. But consequence of sin is death (Romans 6:23) and so Jesus' blood can also protect us from spiritual death. However, this is not a general protection.
But Jesus' blood also purchased the saved. "Be on guard for yourselves and for all the flock, among which the Holy Spirit has made you overseers, to shepherd the church of God which He purchased with His own blood" (Acts 20:28). It brought Jews and Gentiles together in the church. "But now in Christ Jesus you who formerly were far off have been brought near by the blood of Christ" (Ephesians 2:13; also Colossians 1:20).
Nowhere do you find an imagery telling people pray to have Jesus' blood cover them. Jesus' blood was already shed and it is up to people to decide whether to submit to Christ's will to accept the salvation he was offering. Actually, to say you are covered in blood is to say you are guilty of murder.
"So when you spread out your hands in prayer, I will hide My eyes from you; Yes, even though you multiply prayers, I will not listen. Your hands are covered with blood" (Isaiah 1:15).
"For your hands are defiled with blood And your fingers with iniquity; Your lips have spoken falsehood, Your tongue mutters wickedness" (Isaiah 59:3).
"When Pilate saw that he was accomplishing nothing, but rather that a riot was starting, he took water and washed his hands in front of the crowd, saying, "I am innocent of this Man's blood; see to that yourselves." And all the people said, "His blood shall be on us and on our children!"" (Matthew 27:24-25).