The sons of Zebedee answer, We can do that.
This shows their lack of understanding and the consequent over-estimation of themselves. Jesus then says that they will drink his cup and undergo his baptism. He does not say that they can do this, but that they will! And they will be able to do it only by the power of the Spirit and the grace of Christ (Mark 13:9–13; Mark 16:14–20). At this moment Jesus does not delve more deeply into all of this. His answer is simply intended to indicate that they will certainly undergo the undesired suffering, but that the division of the thrones comes only afterwards.
The suffering is not a suffering beside and comparable to that of Jesus. There are no separate cups for the apostles. They will drink from Jesus’ cup of suffering and they will be persecuted and rejected because of him and with him. On this earth the apostles will not become rulers after Easter, but Christ’s sheep to be slaughtered. In the ancient church many commentators applied Jesus’ words exclusively to the martyr’s death. The question then arises if John indeed died as a martyr.1
It is not necessary, however, to think only of death. James suffered as a martyr (Acts 12:2: killed by Herod Agrippa), John as a witness of Christ (John 21:22–24; Revelation 1:9 – your partner in the tribulation
).2 What belongs to Christ (humiliation and suffering) he can also impart to others.3
39 And they said to him, “We are able.” And Jesus said to them, “The cup that I drink you will drink, and with the baptism with which I am baptized, you will be baptized,