"But John left them and returned to Jerusalem."

Why did John Mark leave? Was he afraid of the journey, of the danger? We may never know. We do know that Paul and Barnabas will disagree and even fight on whether to bring John Mark with them, we see this in Acts 15. But this is not something meant to discourage us but rather to give us consolation.

The saints did not simply descend straight from Heaven and were perfect heroes from beginning to end. They were flawed men and women just like us. We should be comforted by the realization that even the Apostles were still human. The saints understand us and our struggles intimately.

For the daily readings, see the USCCB.