In whom are ye also, having heard the word of the truth, the good news of your salvation. A.V. has "in whom ye also trusted," or hoped, supplying a verb from προηλπικότας in Ephesians 1:13, but without the prefix. This seems hardly natural, because the prefix πρὸ is characteristic and emphatic in Ephesians 1:12. It is a much less strain to supply simply ἐστὲ, the important point being that you are now in him—in Christ. This expression, "in Christ," is one of the hinges of the Epistle; it occurs times almost without number, denoting the intimate vital union through faith between Christ and his people, as of the members to the head, in virtue of which they not only get the benefit of his atonement, but share his vital influences, live by faith on the Son of God. Having heard and received the truth as it is in Jesus, the glad tidings of salvation through a crucified Jesus, they became one with him, just as freely as did the believing Jews, and to the same blessed effects. More than that—in whom also having believed, ye were sealed with the Holy Spirit of the promise; thus receiving a new ground for thankfulness, a new proof of the riches of the grace of God. Many explain this seal of baptism, which undoubtedly seals Christ and all his blessings to believers. But though the seal of the Holy Spirit may have been given in and with baptism, it is not identical with baptism. The impression of it is partly within believers and partly without. Within, it is the felt result of the working of the Holy Spirit—the feeling of satisfaction and delight in the work and person of Christ, of love, confidence, and joy flowing out toward God, and the desire and endeavor in all things to be conformed to his will. Without, it is the fruit of the Spirit, the new man, created in righteousness and holiness after the image of Christ. Within, the Spirit bears witness with their spirits; without, the transformed life corroborates the inward witness, and gives it to the world. The first is never complete without the second, nor the second without the first. The spiritual history of believers is thus presented:
The Spirit is called the Spirit of the promise, because he is often promised in the Old Testament (Isaiah 32:15; Ezekiel 36:20; Joel 3:1, etc.).