The Inheritance to the Saints
The same Inheritance proves that the Church the Body of Christ is also Israel Spiritual from the OT, Paul writes Col 1:12-13
12 Giving thanks unto the Father, which hath made us meet to be partakers of the inheritance of the saints in light:
13 Who hath delivered us from the power of darkness, and hath translated us into the kingdom of his dear Son:
This is not a physical inheritance but Spiritual and Heavenly, its the Inheritance promised the Saints of Old and which they looked for and desired, admitting they were pilgrims and strangers to this physical world Heb 11:8-16
8 By faith Abraham, when he was called to go out into a place which he should after receive for an inheritance, obeyed; and he went out, not knowing whither he went.
9 By faith he sojourned in the land of promise, as in a strange country, dwelling in tabernacles with Isaac and Jacob, the heirs with him of the same promise:
10 For he looked for a city which hath foundations, whose builder and maker is God.
11 Through faith also Sara herself received strength to conceive seed, and was delivered of a child when she was past age, because she judged him faithful who had promised.
12 Therefore sprang there even of one, and him as good as dead, so many as the stars of the sky in multitude, and as the sand which is by the sea shore innumerable.
13 These all died in faith, not having received the promises, but having seen them afar off, and were persuaded of them, and embraced them, and confessed that they were strangers and pilgrims on the earth.
14 For they that say such things declare plainly that they seek a country.
15 And truly, if they had been mindful of that country from whence they came out, they might have had opportunity to have returned.
16 But now they desire a better country, that is, an heavenly: wherefore God is not ashamed to be called their God: for he hath prepared for them a city.
Its the Inheritance Paul refers to in Gal 3:16-18
16 Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.
17 And this I say, that the covenant, that was confirmed before of God in Christ, the law, which was four hundred and thirty years after, cannot disannul, that it should make the promise of none effect.
18 For if the inheritance be of the law, it is no more of promise: but God gave it to Abraham by promise.
And its the inheritance Peter writes of here 1 Pet 1:3-5
3 Blessed be the God and Father of our Lord Jesus Christ, which according to his abundant mercy hath begotten us again unto a lively hope by the resurrection of Jesus Christ from the dead,
4 To an inheritance incorruptible, and undefiled, and that fadeth not away, reserved in heaven for you,
5 Who are kept by the power of God through faith unto salvation ready to be revealed in the last time.
Gentiles are included in this Inheritance as the seed of Abraham as we see in Col 1:12 and also Acts 26:17-18
17 Delivering thee from the people, and from the Gentiles, unto whom now I send thee,
18 To open their eyes, and to turn them from darkness to light, and from the power of Satan unto God, that they may receive forgiveness of sins, and inheritance among them which are sanctified by faith that is in me.
Gentiles are called to this Eternal Inheritance Heb 9:15
And for this cause he is the mediator of the new testament, that by means of death, for the redemption of the transgressions that were under the first testament, they which are called might receive the promise of eternal inheritance.