In Him, you also, after listening to the message of truth, the gospel of your salvation—having also believed, you were sealed in Him with the Holy Spirit of promise, who is given as a pledge of our inheritance, with a view to the redemption of God’s own possession, to the praise of His glory. For this reason I too, having heard of the faith in the Lord Jesus which exists among you and your love for all the saints, do not cease giving thanks for you, while making mention of you in my prayers; that the God of our Lord Jesus Christ, the Father of glory, may give to you a spirit of wisdom and of revelation in the knowledge of Him.
I pray that the eyes of your heart may be enlightened, so that you will know what is the hope of His calling, what are the riches of the glory of His inheritance in the saints, and what is the surpassing greatness of His power toward us who believe. These are in accordance with the working of the strength of His might which He brought about in Christ, when He raised Him from the dead and seated Him at His right hand in the heavenly places, far above all rule and authority and power and dominion, and every name that is named, not only in this age but also in the one to come. And He put all things in subjection under His feet, and gave Him as had over all things to the church, which is His body, the fullness of Him who fills all in all.
New American Standard Bible, 1995 Edition
Because St. Paul is writing to Greek Gentiles, he is saying that these Greek Gentiles are already full participants and inheritors of the promise of Abraham which is mentioned in the Old Testament. All of this wonderful news, though, is predicated on the resurrection of Jesus Christ.