Here the word "this" refers to the way the Corinthians responded to Paul's previous letter, as he described in the previous verse. This can be stated in active form. AT: "This is what encourages us" (See: [[rc://en/ta/man/translate/figs-activepassive]])
Here the word "spirit" refers to a person's temperament and disposition. This can be stated in active form. AT: "all of you refreshed his spirit" or "all of you made him stop worrying" (See: [[rc://en/ta/man/translate/figs-activepassive]])