"Thou art no more a servant, but a son" (Galatians 4:7).
On numerous occasions, the Apostle Paul referred to himself and other believers as servants, or slaves. He tells the Galatian believers, however, that they are no longer slaves, but sons. This echoes the words of the Apostle John: "As many as received Him, to they gave He power to become the sons of God, even to them that believe on His name" (John 1:12).
How then are born again believers to view themselves, as sons or servants? The answer is both, but the emphasis must be upon the former, and we must be always careful to affirm ourselves as sons and daughters who serve, as opposed to servants who are also sons and daughters. The order cannot be reversed without doing injury to the sacrifice of the Lord Jesus Christ and its amazing effect of grace whereby God would have us know Him as Father. "But when the fullness of the time was come, God sent forth His Son, made of a woman, made under the law, to redeem them that were under the law, that we might receive the adoption of sons" (Galatians 4:3-5)
Through Christ, believers are children of the most High God. We were adopted into the family of God, to the degree that "because ye are sons, God hath sent forth the Spirit of His Son into your hearts, crying, Abba Father" (Galatians 4:6). The beloved Son, the Lord Jesus, was tortured to death and forsaken by both God and man in order to literally birth us into "the whole family in Heaven and earth" (Ephesians 3:15). God becomes the Father of all who believe in Christ, and the truth of sonship must be joyfully embraced even as we bow our heads in worshipful remembrance of the cost that made such family relationship possible.
Our service to God is the servanthood of "dear children," as opposed to forced laborers (Ephesians 5:1). Love is the motivation, God's love for us, and our love for Him, enabled by the indwelling Spirit of the Lord Jesus. Our Heavenly Father has no interest whatsoever in grudging obedience, performed for hire, as it were (Deuteronomy 28:47; Romans 4:4-5). He rather works to reveal the Lord Jesus' devotion unto us, within us, and by us. Just as our Savior delights to do His Father's will, so do we "delight in the law of God after the inward man" (Romans 7:22). The more we know the person and work of Christ on our behalf, the more our delight for loving service to God becomes conscious and realized. We are sons and daughters who joyously serve the Lord we love, rather than pawns of a domineering master who obey from motives of servile self gratification and fear.
Upon this basis of Christ-wrought affection, commitment, and the willingness for self sacrifice, we voluntarily join Paul in declaring ourselves to be the "servant of God" (Titus 1:1). We also echo the Apostle concerning people: "For though I be free from all men, yet have I made myself servant unto all, that I might gain the more" (I Corinthians 9:19). We live our lives as did the Lord Jesus, who "though He were a Son, yet learned He obedience by the things which He suffered" (Hebrews 5:8). Thereby "He became the author of eternal salvation unto all that obey Him," and thereby we become the ambassadors who call others to the servitude of sons and daughters beloved by the Father, united with the Son, and birthed by the Holy Spirit into familial and eternal kinship with the living God.
"Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when He shall appear, we shall be like Him; for we shall see him as He is."
(I John 3:2)