The betrayal

Mark 14:43 And immediately, while he yet spake, cometh Judas, one of the twelve, and with him a great multitude with swords and staves, from the chief priests and the scribes and the elders. Matt 26:47 And while he yet spake, lo, Judas, one of the twelve, came, and with him a great multitude with swords and staves, from the chief priests and elders of the people. Luke 22:47a And while he yet spake, behold a multitude, and he that was called Judas, one of the twelve, went before them, John 18:3 Judas then, having received a band of men and officers from the chief priests and Pharisees, cometh thither with lanterns and torches and weapons.
Mark 14:44 And he that betrayed him had given them a token, saying, Whomsoever I shall kiss, that same is he; take him, and lead him away safely.45 And as soon as he was come, he goeth straightway to him, and saith, Master, master; and kissed him. Matt 26:48 Now he that betrayed him gave them a sign, saying, Whomsoever I shall kiss, that same is he: hold him fast.49 And forthwith he came to Jesus, and said, Hail, master; and kissed him. Luke 22:47b and drew near unto Jesus to kiss him. John 18:4 [1] Jesus therefore, knowing all things that should come upon him, went forth, and said unto them, Whom seek ye? 5 They answered him, Jesus of Nazareth. Jesus saith unto them, I am he. And Judas also, which betrayed him, stood with them.
      John 18:6 As soon then as he had said unto them, I am he, they went backward, and fell to the ground. 7 Then asked he them again, Whom seek ye? And they said, Jesus of Nazareth. 8 Jesus answered, I have told you that I am he: if therefore ye seek me, let these go their way: 9 That the saying [2] might be fulfilled, which he spake, Of them which thou gavest me have I lost none.
Matt 26:50a And Jesus said unto him, Friend, wherefore art thou come? Luke 22:48 But Jesus said unto him, Judas, betrayest thou the Son of man with a kiss?
Mark 14:46 And they laid their hands on him, and took him. Matt 26:50b Then came they, and laid hands on Jesus, and took him.

[1]John's account of Jesus' capture cannot be reconciled with the other gospels.

[2]See John 10:28 and 17:12.