A famous two-verse variant appears in Luke 22:43-44. In the middle of Jesus's agony in the garden of Gethsemane, we read that "an angel from heaven appeared to him and strengthened him. And being in anguish, he prayed more earnestly, and his sweat was like drops of blood falling to the ground." The NIV offers the following footnote at this point: "Many early manuscripts do not have verses 43 and 44." Many others do. The external evidence is quite split: about half of the oldest and most reliable manuscripts contain these sentences, and about half don't. The vast majority of all the late manuscripts contain them, but their evidence doesn't weigh that heavily in a decision. There is nothing terribly "hard" about this reading, especially when we realize that Luke is employing a simile: Jesus's sweat is like drops of blood. The text does not say he actually sweats blood. So it seems more likely that some overly pious scribe wanted to add a supernatural dimension to the story, with the role of the angel strengthening Christ, than that someone omitted these verses despite finding them in the manuscript he was copying.
(Craig L. Blomberg, Can We Still Believe the Bible? [Grand Rapids, Michigan: Brazos Press, 2014], 23).Blomberg gets the manuscript evidence wrong. As Blumell notes that many scholars misconstrue the manuscript evidence for the passage "and so our earliest extant piece of manuscript evidence for Luke 22 attests vv. 43–44!" (p. 6). Blumell also shows that early Christian authors note embarrassment over the notions that Jesus suffered in the garden (any good Stoic should know that a real man can face pain and torture) and also note that Christian copyists had deleted the passage.
One has to wonder, since Blomberg is defending the tampered text as inerrant what does that say about his inerrancy arguments?