Mark 4:40

And he said unto them, Why are ye fearful? have ye not yet faith?

It is ridiculous to make a big thing out of the fact that Matthew recorded this question as taking place before the great calm. Could Jesus not have said it twice? Besides that, the oldest historical reference to the gospel of Mark stated quite flatly that:

Mark, having been Peter's interpreter, wrote all that Peter related; though he did not record in order that which was said or done by Christ.[48]

This quotation was attributed to an apostolic presbyter by Papias in 130 A.D.

The apostles of Christ were slow, even with all the advantages they had, to understand fully the divine nature and power of Jesus, whose question here exhibits some element of surprise at their dullness.