Chizuk Emunah (Pt 2) Under the Microscope: Chapter 56

John 18:3-5, etc., "Judas Iscariot having received a band of men from the chief priests and pharisees, cometh with lanthorns," etc., and was asked by Jesus, "Whom seek ye? and they answered and said, Jesus of Nazareth. Jesus saith unto them, I am he. And Judas also, who betrayed him, stood with them." This account of the betrayal differs from that given in Matthew 26:47; Mark 14:43; and Luke 22:47; for according to those authors of the respective parts of the Gospel, Judas gave a secret sign to his companions, saying, "Him whom I shall kiss, that same is he, hold him fast.

Now we get to a better objection. From Mark's account:

And immediately, while he was still speaking, Judas came, one of the twelve, and with him a crowd with swords and clubs, from the chief priests and the scribes and the elders. Now the betrayer had given them a sign, saying, “The one I will kiss is the man. Seize him and lead him away under guard.” And when he came, he went up to him at once and said, “Rabbi!” And he kissed him. And they laid hands on him and seized him.

John's account differs in the details:

Now Judas, who betrayed him, also knew the place, for Jesus often met there with his disciples. So Judas, having procured a band of soldiers and some officers from the chief priests and the Pharisees, went there with lanterns and torches and weapons. Then Jesus, knowing all that would happen to him, came forward and said to them, “Whom do you seek?” They answered him, “Jesus of Nazareth.” Jesus said to them, “I am he.” Judas, who betrayed him, was standing with them. When Jesus said to them, “I am he,” they drew back and fell to the ground. So he asked them again, “Whom do you seek?” And they said, “Jesus of Nazareth.” Jesus answered, “I told you that I am he. So, if you seek me, let these men go.” 

 Again, John' account has a great deal more explanation from the narrator. Let me state the response from A. Lukyn Williams before giving my own

To a reader of history, and, we venture to say, much more to a writer of history, it seems absurd to argue from these verbal differences that the narrative is untrustworthy. Differences in unimportant details are rather the proof, not the denial, that the testimony of witnesses is true (cf. par 298). Here both sets of persons testify to the all-important point that Judas was guide to them that took Jesus. Whether he actually did, or did not, carry out his proposal to kiss His Master as a sign to the soldiers, matters very little. According to John, our Lord seems to have forestalled him, and to have made the kiss which followed only an act of hypocrisy towards Himself, and no longer also a sign to the soldiers. Why blame the Synoptic Gospels for not stating this at length? It is to be feared that Jews treat the New Testament with wilful injustice. They do not accord to it the same measure of reverent study, of historical common sense, which they pay to the Old Testament. Yet every Jew will grant that when two passages of the Law speak of the same thing, one passage may be fuller than the other, without either being wrong. What says R. Nehemiah in T. J. Rosh haShanah, III. 5 (58d)? "The words of the Law are poor in one place and rich in another." So, too, we find, in Bemidbar R., Chapter 19, towards the end (on Num 21:21) "All the words of the Law need each other; for what one closes, another opens." See also Tanchuma on the same passage, ed. Buber, p. 129. If this be granted to the Law, why refuse it to the Gospel? 

 Williams is right about the inconsistent double standard. When God says "remember the Sabbath" in Exodus and "guard the Sabbath" in Deuteronomy, the rabbis do not take this to be a contradiction, but say that God said both at the same time.

If you read the two accounts closely, there is no explicit contradiction. It could have been the case that Judas came up and kissed Jesus. The soldiers then marched toward him and initiated the conversation we read in John.

For futher viewing, I recommend Mike Licona's lecture about the gospels as ancient Greco-Roman biographies. Skeptics complain about differences between the gospel accounts, but Licona mentions that Plutarch's own accounts of different people's lives contain many of the same kinds of differences, even though they are all written by the same author. Plutarch, for example, tells of the assassination of Julius Caesar 5 different times, and it is not easy to come up with a harmonization which allows all of them to be interpreted literally.

Licona notes that ancient biographies gave a general idea of the historical figure, rather than giving exact details. Think of this as the difference between painting a portrait vs. taking a photograph. Portrait artists are allowed creative liberties without being criticized as erroneous.

So if you insist that these books have to be harmonized down to the minute detail, this account is pretty easy to harmonize with the other gospel accounts. If you do not require such adherence to detail, recognize that these differences would not have been seen as errors by ancient readers, but more like creative liberties taken by the authors.