In 4:6 Paul says that God has sent forth the Spirit of His Son into our hearts. Actually, the Spirit of God came into our spirit at the time of our regeneration (John 3:6; Rom. 8:16). Because our spirit is hidden in our heart (1 Pet. 3:4), and because the word here refers to a matter that is related to our feeling and understanding, both of which belong to our heart, Galatians 4:6 says that the Spirit of God’s Son was sent into our hearts.
The parallel verse, Romans 8:15, says that we who have received a spirit of sonship cry in this spirit, “Abba, Father!” whereas Galatians 4:6 says that the Spirit of God’s Son is crying in our hearts, “Abba, Father!” This indicates that our regenerated spirit and the Spirit of God are mingled as one, and that our spirit is in our heart. This indicates also that the sonship of God is realized by us through our subjective experience in the depth of our being. In this verse, Paul appealed to such an experience of the Galatian believers for the supporting of his revelation. This appeal was quite convincing and subduing because it contained not only objective doctrines but also subjective, experiential facts.
Abba is an Aramaic word, and Father is the translation of the Greek word Pater. Such a term was used first by the Lord Jesus in Gethsemane while He was praying to the Father (Mark 14:36). The combining of the Aramaic title with the Greek title expresses a stronger affection in crying to the Father. Such an affectionate cry implies an intimate relationship in life between a genuine son and a begetting father. What a marvelous fact it is that we are sons of God! We have the assurance that we are truly God’s sons because in our spirit we can sweetly cry, “Abba, Father.”
As human beings, we have not only a spirit but also our person, our being. The center of our person is our heart. For us to become sons of God involves not only our spirit but also our heart as the center of our personality. Since the spirit is in the heart (1 Pet. 3:4), it is not possible for the Spirit to be sent into our spirit without also being sent into our heart. It is important for us to realize that our spirit is the kernel, the central part, of our heart. When God’s Spirit was sent into our spirit, the Spirit was sent into the kernel of our heart. When the Spirit cries within us, He cries from our spirit and through our heart. Hence, concerning sonship, our heart must be involved.
The inner sense we have as we call on the Lord from our spirit through our heart is mainly in the heart, not in the spirit. This implies that to be genuinely spiritual we need to be emotional in a proper way. We are not senseless statues; we are human beings with feelings. Therefore, the more we cry “Abba, Father” in the spirit, the deeper the sweet and intimate sense will be in our heart.
The sense we have when calling in this way is sweet and intimate. Although the Spirit of sonship has come into our spirit, the Spirit cries in our hearts, “Abba, Father!” This indicates that our relationship with our Father in the sonship is sweet and very intimate. How tender and sweet it is to call God, “Abba, Father”! Such an intimate calling involves our emotion as well as our spirit. The Spirit of sonship in our spirit cries “Abba, Father” from our heart. This proves that we have a genuine, bona fide relationship in life with our Father. We are His real sons.
In Galatians 4:7 Paul continues, “So then you are no longer a slave but a son; and if a son, an heir also through God.” The New Testament believer is no longer a slave to works under law but is a son in life under grace. Instead of the law that keeps us in custody, we have the all-inclusive Spirit, who is everything to us. Whereas the law could not give life, the Spirit gives life and brings us into maturity that we may have the full position and right of sons. The custody of the law has been replaced by the Spirit of sonship.
As sons, we also are heirs through God. An heir is one who is of full age according to the law (the Roman law is used for illustration) and who is qualified to inherit the father’s estate. The New Testament believers become heirs of God not through the law or through their fleshly father but through God, even the Triune God—the Father, who sent forth the Son and the Spirit (vv. 4, 6); the Son, who accomplished redemption for sonship (v. 5); and the Spirit, who carries out the sonship within us (v. 6).