What happens the moment a person is saved regarding sonship and inheritance?
At salvation, the Holy Spirit causes a person to be born into the family of God. Immediately, God performs another act: He places that believer as a full heir with Jesus Christ, a joint heir, not merely a future beneficiary. This grants equality with Christ in inheritance, enabling the believer to say Abba Father.
Les explains that when a son had reached that age and was ready for that position with the father, they went through the rites of adoption. The word means being placed as a full son and full partner with the Father, not merely one born into the family, nor one legally taken from another family, but one trained, tutored, and prepared. Les teaches that the glory of this is that the moment a person is saved, he is born into the family of God, and immediately God also places him as the full heir with Jesus Christ. This is not attained by striving or by working twenty years as Jacob did for his wives; it comes the moment one believes. That is why the believer can say Abba Father, as in verse 15. Verse 17 confirms that if we are children, then we are heirs, not a distant heir hoping for a small inheritance, but a joint heir. Les points out that joint heir implies equality: what is His is hers, and vice versa.