12. Teaching--Greek, "disciplining us." Grace exercises discipline, and is imparted in connection with disciplining chastisements (1Co 11:32; Heb 12:6, 7). The education which the Christian receives from "the grace" of God is a discipline often trying to flesh and blood: just as children need disciplining. The discipline which it exercises teaches us to deny ungodliness and worldly lusts, and to live soberly, righteously, and godly, in this present world (Greek, "age," or course of things) where such self-discipline is needed, seeing that its spirit is opposed to God (Tit 1:12, 16; 1Co 1:20; 3:18, 19): in the coming world we may gratify every desire without need of self-discipline, because all desires there will be conformable to the will of God.
      that--Greek, "in order that"; the end of the "disciplining" is "in order that . . . we may live soberly," &c. This point is lost by the translation, "teaching us."
      denying . . . lusts-- (Lu 9:23). The Greek aorist expresses "denying once for all." We deny "worldly lusts" when we withhold our consent from them, when we refuse the delight which they suggest, and the act to which they solicit us, nay, tear them up by the roots out of our soul and mind [ST. BERNARD, Sermon 11].
      worldly lusts--The Greek article expresses, "the lusts of the world," "all worldly lusts" [ALFORD], (Ga 5:16; Eph 2:3; 1Jo 2:15-17; 5:19). The world (cosmos) will not come to an end when this present age (aeon) or course of things shall end.
      live soberly, righteously, and godly--the positive side of the Christian character; as "denying . . . lusts" was the negative. "Soberly," that is, with self-restraint, in relation to one's self: "righteously" or justly, in relation to our neighbor; "godly" or piously, in relation to God (not merely amiably and justly, but something higher, godly, with love and reverence toward God). These three comprise our "disciplining" in faith and love, from which he passes to hope (Tit 2:13).

JFB.