Mark speaks of miracles as though they were people going along with the believers. Alternate translation: "People watching those who believe will see these things happen and know that I am with the believers" (See: [[rc://en/ta/man/translate/figs-personification]])
Possible meanings are 1) Jesus is giving a general list: "In my name they will do things like these: They" or 2) Jesus is giving an exact list: "These are the things they will do in my name: They."
Here "name" is associated with Jesus's authority and power. See how "in your name" is translated in [Mark 9:38](../09/38.md). Alternate translation: "By the authority of my name" or "By the power of my name" (See: [[rc://en/ta/man/translate/figs-metonymy]])