What does Mark 14:19 mean?

This is an interesting reaction to Jesus' words. For three years, the disciples have dreamt about what Jesus' victory and kingdom will mean for them (Matthew 19:28; Mark 10:35–37). Even during this meal, they argue over who is greatest (Luke 22:24–30). And they reject or fail to understand Jesus' prophecies about a bleaker future (Mark 8:31–33; 9:30–32; 10:32–34).

Now, Jesus tells them that one of them will betray Him. With these words, the disciples' confidence is temporarily shattered. They trust Jesus' prediction. Their thoughts don't go to the power and authority they will lose; they are genuinely sorrowful and filled with a humble fear that is uncommon to them. Each disciple is looking into his heart to see if he has the capacity to betray Jesus, and each one is afraid he does.

Only one disciple will betray Jesus. Another will deny knowing Him (Mark 14:66–72), and ten more will abandon Him (Mark 14:50), with only John returning at some point to witness the crucifixion (John 19:26–27) It's important to see the distinctions because the three reactions express three different theological conditions.

Readers must understand that at this point, the disciples are under the old covenant and hold a Jewish theology of salvation. Their sense of atonement for sin is entirely tied to the sacrifices they perform. They do not yet have the indwelling of the Holy Spirit (Acts 2:1–4) which will seal them for eternity (Ephesians 1:13–14). The disciples will "scatter," from the Greek root word diaskorpizo. They will prove that in themselves, they are chaff, easily blown away by the wind.

Peter will "deny" Jesus, from the Greek root word aparneomai. He will choose not to identify with the Man he has followed and pledged himself to for the last three years.

Both infidelities are recoverable. After the resurrection, the disciples will gather to Jesus again, and Peter will spend the rest of his life strongly identifying with Christ.

Judas, however, "betrays" Jesus, from the Greek root word paradidomi. Like an apostate, he makes a conscious, permanent break in his association with Jesus. He appeared to be with Jesus and has heard what Jesus has to say, but he rejects Jesus' teaching and breaks away (1 John 2:19). Perhaps worst of all, when he realizes his mistake, instead of repenting he deliberately removes himself from any possibility of living to see God's forgiveness (Matthew 27:3–10).

It is good to do what the disciples do here: consider how we are betraying Jesus in our lives. But don't be like Judas. Remember that however we find we are betraying God, He will forgive us if we turn to Him.