Paul speaks of Christ's sufferings as if they were objects that could increase in number. AT: "For just as Christ suffered greatly for our sake" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Possible meanings are 1) that this refers to the suffering that Paul and Timothy experience because they preach the message about Christ or 2) that this refers to the suffering that Christ experienced on their behalf.
Here the word "we" refers to Paul and Timothy, but not to the Corinthians. This can be stated in active form. AT: "But if people afflict us" (See: [[rc://en/ta/man/translate/figs-exclusive]] and [[rc://en/ta/man/translate/figs-activepassive]])
# if we are comforted
This can be stated in active form. AT: "if God comforts us" (See: [[rc://en/ta/man/translate/figs-activepassive]])