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. Alternate translation: "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. Alternate translation: "all of you refreshed his spirit" or "all of you made him stop worrying" (See: [[rc://en/ta/man/translate/figs-activepassive]])