The verbs are left out of these phrases but they are understood. AT: "If we are children of God, then we are also heirs" (See: [[rc://en/ta/man/translate/figs-ellipsis]])
The phrases "on the one hand" and "on the other hand" introduce two different ways of thinking about something. AT: "heirs of God and also fellow heirs with Christ" (See: [[rc://en/ta/man/translate/figs-idiom]])