The words "I do this" are understood from the previous phrase. Alternate translation: "But if I do this unwillingly" or "But if I do this even though I do not want to" or "But if I do this because I was forced to do it" (See: [[rc://en/ta/man/translate/figs-ellipsis]])
This can be stated in active form. Alternate translation: "I still must complete this work that God entrusted to me" or "I still must do this work that God gave me to complete" (See: [[rc://en/ta/man/translate/figs-activepassive]])