Romans 8:14-15 ESV - For all who are led by the Spirit of God are sons of God. 15 For you did not receive the spirit of slavery to fall back into fear, but you have received the Spirit of adoption as sons, by whom we cry, “Abba! Father!”
1 John 5:19 NLT - We know that we are children of God and that the world around us is under the control of the evil one.
Imagine living as a citizen of ancient Rome where the law gave fathers absolute and total authority over the family. This authority applied throughout the fathers’ lives and was not changed just because the children became adults. The children were vital to a Roman family’s future. Because of this, Roman adoption would often occur as one father would transfer his role and power over his child to another man. Adopting adults (or nearly adults) was the main method. Consider the view of the Roman adoption principles that the Apostle Paul used to teach spiritual reality in Christ to the church at Rome. The adopted son became heir to his new father’s estate. So we who have received the Spirit of adoption are “joint-heirs” with Christ Himself. The inheritance as children of God - an eternal inheritance, a perfect inheritance - has been promised. We who receive the seal of the Spirit have received God’s down payment while we await our final resurrection. What rights and privileges as an adopted child of God may you want to begin using to bless others? Do you see how blessed and important it is to have the Spirit of Christ living in you? (“Living in you” not just a past experience but active present action)
Ephesians 1:13-14 NIV - And you also were included in Christ when you heard the message of truth, the gospel of your salvation. When you believed, you were marked in him with a seal, the promised Holy Spirit, 14 who is a deposit guaranteeing our inheritance until the redemption of those who are God’s possession—to the praise of his glory.