Does the Christian rejoice that they are a child of God and an heir to the coming glory? Through his sermon on Romans 8:17 titled “Heirs According to the Promise,” Dr. Martyn Lloyd-Jones joyfully proclaims that every time that Paul references the Spirit being a seal, he also mentions that the Spirit is the guarantor of the fact that believers are heirs with Christ. This fact is great assurance and certainty of the Christian faith: if Christians are children of God, then they are also His heirs. Paul once again demonstrates that believers have union with Christ; it is absolute and cannot end. Dr. Martyn Lloyd-Jones expresses that only Christians have this kind of hope. The inheritance of glory for Christians was set before the beginning of time in God. This is a great promise and is shown often throughout Scripture. All believers are joint heirs with Christ and should be looking toward the coming of their Savior.

http://www.mljtrust.org/sermons/heirs-according-to-the-promise/