Mar 6:50 Be of good cheer: it is I; be not afraid.
Alternative: "Don't be afraid. It is I. Don't be alarmed."

I found Matthew's Gospel was surprising consistent in terms of every chapter having a specific focus or topic. Mark is not proving to be as consistent in terms of theme. This chapter began as a discussion of society and our social interactions, but it seems to have changed. The focus has changed from society to our physical needs in the last verse. In this verse, that theme is continued, asking us simply to stop being afraid of the physical universe. What happens is art of God's plan. We do not need to fear it. It all has purpose and meaning.

Perhaps the larger lesson here is that God is in everything: society and physical reality. If we simply accept God's plan, we can deal with each challenge as it comes without fear or concern. Life isn't meant to be a bowl of cherries. It is meant to challenge us so we can grow. Fear stands in the way of us learning from each setback and sadness.

"Be of good cheer" is from tharseô (tharseo), which means "fear not," "have courage," "have confidence," "have no fear," and "make bold."

"It is" is from eimi (eisi), which means "to be,""to exist," "to be the case," and "is possible."

"Afraid" is from phobeô, (phobeo) which means "to put to flight, "terrify," "alarm," "to stand in awe," and "to be afraid."