|This article has a real world counterpart outside of Left Behind.|
|This subject has a counterpart in the real world. However, information in this article comes from the fictional universe of the Left Behind franchise.|
Blood is a body fluid found in the circulatory system of living beings. In the Bible, blood is an important symbol, as it is used for the life of all living beings, that the shedding of blood from a sacrifice that is acceptable to God is His means for atonement for sin, and is also used for judgment against man's sins. According to the New Testament, Jesus' blood was shed on the cross as sufficient payment for all men's sins.
In the Left Behind series, blood appears in various judgments God has sent upon mankind during the Tribulation. In the first Trumpet Judgment, hail and fire mingled with blood fell upon the earth as a third of all trees as well as all vegetation was destroyed. In the second Trumpet Judgment, a burning mountain that fell from the sky had turned a third of the seas into blood. In the second and third Bowl Judgments, the seas and springs of water were all turned to blood, causing those who have taken the "mark of loyalty" and worshiped Carpathia's image to suffer and die from dehydration, since God considered it just due for their shedding the blood of His saints.
Also the two witnesses Eli and Moishe, as well as Chaim Rosenzweig who was disguised as the prophet Micah, had the power to turn water into blood, with one instance of doing such making Nicolae Carpathia gag and curse the believers gathered at Teddy Kollek Stadium for doing such a thing toward him, accusing them of deliberately trying to poison him.
In The Remnant and Armageddon, the world's salt and fresh waters are turned into blood for a period of time, killing all water life that had not been safeguarded in aquariums. The Global Community attempts to construct filtering plants, but due to corruption and understaffing, they are only marginally successful. On the other hand, believers in Christ were able to get fresh clean drinking water from the bloody springs. The wonder worker named Orcus swayed unbelievers that wandered out of Petra to see his signs and wonders by showing them he could produce a spring of fresh water for them to drink, but later that same spring ended up producing blood.
In Glorious Appearing, the slaughter of the Global Community Unity Army produced a river of blood that rose up to the height of horses' bridles for a length of 1600 furlongs or stadia (about 200 miles), fulfilling Revelation 14:19-20, which stained Jesus' robe when He walked through the mess.
It is not known what blood type the supernaturally created or converted blood is, as there are no attempts shown to run medical tests on it.