Jamieson, Fausset and Brown on Titus 3:7

7. That, &c.--the purpose which He aimed at in having "saved us" (Tit 3:5), namely, "That being (having been) justified (accounted righteous through faith at our 'regeneration,' and made righteous by the daily 'renewing of the Holy Ghost') by His grace (as opposed to works, Tit 3:5) we should be made heirs."

his grace--Greek, "the grace of the former," that is, God (Tit 3:4; Ro 5:15).

heirs--(Ga 3:29).

according to the hope of eternal life--Tit 1:2, and also the position of the Greek words, confirm English Version, that is, agreeably to the hope of eternal life; the eternal inheritance fully satisfying the hope. Bengel and Ellicott explain it, "heirs of eternal life, in the way of hope," that is, not yet in actual possession. Such a blessed hope, which once was not possessed, will lead a Christian to practice holiness and meekness toward others, the lesson especially needed by the Cretans.