by Dr. Thomas Hudgins, translator of Aprenda a Leer el Griego del Nuevo Testamento
How did Jesus go from walking around Galilee, teaching the multitudes, healing the sick, and dining in people’s homes to having his body marred more than any other human in history and eventually giving his life for the sins of the world on the cross? Well, there are a number of ways we can approach this question, such as by focusing on the religious elite of Jesus’ day and how they wanted Jesus dead and out of the way. But I want to turn our attention to Satan and Judas Iscariot, paying special attention to where Judas’ life intersects with the workings of the evil one.
The Gospels tell us that Satan was actively involved in leading Jesus to the cross. Maybe you recall where it says in one of the Gospels that Satan “entered into Judas” during the last week of Jesus’ life. But this begs the question, “To which Gospel am I referring?” I say that because there are actually two references in the Gospels to Satan entering into Judas—one in Luke, and one in John. And there are a couple of details that make these reports difficult. So, let’s look at each account and then we can step back and make some observations. I have placed in italics the text indicating Satan entered into Judas.
 
The first report is found in the Gospel of Luke:

Now the Feast of Unleavened Bread, which is called the Passover, was approaching. The chief priests and the scribes were trying to figure out a way they could put him to death; for they were afraid of the people. And Satan entered into Judas who was called Iscariot, who was one of the twelve. And he went away and discussed with the chief priests and officers how he might betray him to them. They were glad and agreed to give him money. So he consented, and began seeking a good opportunity to betray him to them apart from the crowd. Then came the first day of Unleavened Bread on which the Passover lamb had to be sacrificed. And Jesus sent Peter and John, saying, “Go and prepare the Passover for us, so that we may eat it.” (Luke 22:1–8)

The second report is found in the Gospel of John:

When Jesus had said this, he became troubled in spirit, and testified and said, “Truly, truly, I say to you, that one of you will betray me.” The disciples began looking at one another, at a loss to know of which one he was speaking. One of his disciples, the one who Jesus loved, was reclining on Jesus’ bosom. So Simon Peter signals to him, and says to him, “Figure out who Jesus is talking about.” He, leaning back on Jesus’ bosom, say to him, “Lord, who are you talking about?” Jesus then answers, “The one for whom I shall dip the morsel and give it to him.” So when he had dipped the morsel, He takes it and gives it to Judas, the son of Simon Iscariot. After the morsel, Satan entered into him. Therefore Jesus says to him, “That which you are doing, do it quickly.” Now no one that was reclining at the table knew for what purpose he had said this to him. Some thought he said it because Judas was in charge of money box, and Jesus was basically saying to him, “Buy the things we need for the feast”; the other option was he was saying Judas should give something to the poor. So after receiving the morsel he went out immediately; and it was night. (John 13:21–30)

Alright, so you can tell there is something going on here in the accounts that needs our attention. According to Luke, Satan enters Judas before the disciples sit down to celebrate the Passover. In fact, according to Luke, it takes place before the plans for the Passover meal are finalized. According to John, Satan enters into Judas during the Passover meal. Luke mentions demonic possession in a number of places (Luke 8:30, 33). John, however, makes no such mention in his Gospel, well except one. The sole mention of possession in the Gospel of John is this entrance of Satan into Judas. So how many times did Satan enter into Judas—once, twice, or never at all? And why did Satan enter into Judas, or, depending on how you answer the first question, why did the authors of their respective Gospels indicate that Satan did so?
I’m going to go ahead and show my cards. I think Satan entered into Judas twice. Part of the reason I answer this way has to do with what I think about the Scriptures. They are inspired by God and, as a result, they are true in the reports they present. They are totally accurate and the accuracy of their content flow out of the very character of God, for whom it is impossible to lie. Even if someone does not agree with this view on biblical inspiration, the evidence in John supports two entrances of Satan into Judas. John does not directly mention the entrance found in Luke. Why not? Well, John focuses heavily on sharing material that is not found in the other Gospels. And John focuses heavily on describing the events of the last night of Jesus’ life (John 13ff.). Even though John does not specifically mention the entrance found in Luke, he does seem to make an indirect reference to it. He writes:

During supper, the devil having already put into the heart of Judas Iscariot, the son of Simon, to betray him, Jesus, knowing that the Father had given all things into his hands, and that he had come forth from God and was going back to God, gets up from supper, and lays aside his garments; and taking a towel, he girded himself. (John 13:2)

When John indicates that the devil (i.e., Satan) had already put the desire to betray Jesus in the heart of Judas, he is probably referring to the account found in Luke. John specifically mentions Satan’s involvement in this desire. He put the desire inside Judas. And apparently he needed to enter Judas in order to accomplish this end. Satan enters Judas the first time to put the idea in Judas’ mind and heart. And considering how Satan is presented in other texts (e.g., Genesis 3; Matthew 4), he probably did everything he could to make the idea as appealing as possible. Just think, if Satan could take Jesus up to a mountain and show him all the kingdoms of the world and their glory (and offer them to Jesus in return for his worship), how appealing would he make this opportunity to betray Jesus and in exchange for what (though an offer is nowhere mentioned in the Gospels or elsewhere)?
So Luke records this first entrance. That moment is the first time Satan shows up personally and out front in the plan to get Jesus to the cross. Luke foreshadowed this moment after the temptation: “When the devil had finished every temptation, he left him until an opportune time” (Luke 4:13, emphasis added). That first entrance into Judas was this opportune time, and Satan would take a very active role leading up to the cross from that point forward, both with the betrayal of Jesus and the temptation of some (possibly all) of his apostles. I say some of his apostles (plural), not one of his apostles. The reason is because Jesus told Peter leading up to the cross that Satan was going to tempt him and the other apostles: “‘Simon, Simon, behold, Satan has demanded permission to sift you (plural) like wheat; but I have prayed for you (singular), that your faith may not fail; and you, when once you have turned again, strengthen your brothers’” (Luke 22:31–32). The mention of the first entrance by Luke connects the dots from Luke 4 to Luke 22, and it reminds Theophilus and his greater audience that the cross has not only the attention of all of heaven, but that of all of the domain of darkness as well. John connects the dots as well. His Gospel in many ways is the “behind-the-scenes” Gospel, providing us with some very important and always interesting details about the life of Jesus. The second entrance of Satan into Judas is one of the many offered by John. In the first entrance, Satan plants the idea in Judas’ mind and heart. In the second one, he executes the plan and secures that Jesus will be taken into custody.