Mark 14:44

‘Now he who betrayed him had given them an agreed signal saying, “Whoever I will kiss, that is he. Take him and lead him away safely.” '

What sympathy can we have for Judas when he planned it all so cynically? He did not want to be seen as denouncing Jesus and so he would do it by a kiss of friendship. So psychologically do treacherous people behave when they cannot face the reality of what they are doing. He was the betrayer and yet he wanted to feel as if he had had no real part in it.

The need for some sign possibly demonstrates that the arresting party were concerned lest in the confusion and the darkness they should arrest the wrong man and lose the opportunity. They would flinch at the thought of what would have happened if they did and the news got out to the Passover crowds from Galilee. It certainly demonstrated that Judas wanted to make sure there was no mistake. They had probably expected to find the disciples in a group in the moonlit darkness, with Jesus among them, in a place where there were other groups around. (There would be many groups around that night). The sign suggests that they were hoping to carry out the arrest before any outsider realised what was happening. Judas' approach would not appear belligerent and there would hopefully be uncertainty and therefore no resistance until too late.

They were not to know that Jesus would actually come to meet them, rendering it unnecessary. Even Judas did not know or expect that.