To the only ... God our Saviour - The oldest manuscripts add, “through Jesus Christ our Lord.” The transcribers, fancying that “Savior” applied to Christ alone, omitted the words. The sense is, To the only God (the Father) who is our Savior through (that is, by the mediation of) Jesus Christ our Lord.
dominion - Greek, “might.”
power - authority: legitimate power. The oldest manuscripts and Vulgate, after “power,” have “before all the age,” that is, before all time as to the past: “and now,” as to the present; “and to all the ages,” that is, for ever, as to the time to come.