The Inheritance

Galatians 3:

2  Let me ask you only this: Did you receive the Spirit by works of the law or by hearing with faith?

3  Are you so foolish? Having begun by the Spirit, are you now being perfected by the flesh?

18  For if the inheritance comes by the law, it no longer comes by promise; but God gave it to Abraham by a promise.

Ephesians 1:

11  In him we have obtained an inheritance, having been predestined according to the purpose of him who works all things according to the counsel of his will,

12  so that we who were the first to hope in Christ might be to the praise of his glory.

13  In him you also, when you heard the word of truth, the gospel of your salvation, and believed in him, were sealed with the promised Holy Spirit,

14  who is the guarantee of our inheritance until we acquire possession of it, to the praise of his glory.

Col 1:

11  May you be strengthened with all power, according to his glorious might, for all endurance and patience with joy,

12  giving thanks to the Father, who has qualified you to share in the inheritance of the saints in light.

13  He has delivered us from the domain of darkness and transferred us to the kingdom of his beloved Son,

14  in whom we have redemption, the forgiveness of sins.

Hebrews 9:

13  For if the blood of goats and bulls, and the sprinkling of defiled persons with the ashes of a heifer, sanctify for the purification of the flesh,

14  how much more will the blood of Christ, who through the eternal Spirit offered himself without blemish to God, purify our conscience from dead works to serve the living God.

15  Therefore he is the mediator of a new covenant, so that those who are called may receive the promised eternal inheritance, since a death has occurred that redeems them from the transgressions committed under the first covenant.

1Peter 1:

3  Blessed be the God and Father of our Lord Jesus Christ! According to his great mercy, he has caused us to be born again to a living hope through the resurrection of Jesus Christ from the dead,

4  to an inheritance that is imperishable, undefiled, and unfading, kept in heaven for you,

5  who by God's power are being guarded through faith for a salvation ready to be revealed in the last time.

1Cor 15:50  I tell you this, brothers: flesh and blood cannot inherit the kingdom of God, nor does the perishable inherit the imperishable.

1John 3:

1  See what kind of love the Father has given to us, that we should be called children of God; and so we are. The reason why the world does not know us is that it did not know him. 2  Beloved, we are God's children now, and what we will be has not yet appeared; but we know that when he appears we shall be like him, because we shall see him as he is.

The indwelling Holy Spirit is the guarantor (here and now) of the inheritance in which all the sons of God share. That is, we now share in the eternal life given us by the Son according to the Father's will (John 17:1-2), and will one day physically share in His immortality. Therefore we work out, in Godly fear and awe, what God has both willed and worked into us, according to His good pleasure. (Philippians 2:12-13)
No wonder Paul spoke so strongly against the judaizers and legalists of His day. They outright deny God's finished work through Christ and the "gift" of His Holy Spirit, given freely as seal for those whom He has called.

Romans 5:5 and hope does not put us to shame, because God's love has been poured into our hearts through the Holy Spirit who has been given to us.