Every Christian is a child of God but not every Christian is a son of God.
Galatians 4:1 I mean that the heir, as long as he is a child, is no different from a slave, though he is the owner of everything,
Ephesians 4:14-15 so that we may no longer be children, tossed to and fro by the waves and carried about by every wind of doctrine, by human cunning, by craftiness in deceitful schemes. (15) Rather, speaking the truth in love, we are to grow up in every way into him who is the head, into Christ.
Here we see that God wants us to grow from just being children of God into becoming mature sons of God who operate as kings and princes.
Why is God not satisfied with us just being children of God?
Children have limited wisdom and maturity and so cannot inherit the fullness of God’s anointing and so fulfill the fullness of His purposes: to be conformed to the image of Christ and so disciple every tongue, tribe and kindred by the preaching and demonstration of the fullness of the gospel of the Kingdom and so close this age and dispensation:
Romans 8:28-29 And we know that for those who love God all things work together for good, for those who are called according to his purpose. (29) For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that he might be the firstborn among many brothers.
Ephesians 4:11-13 And he gave the apostles, the prophets, the evangelists, the shepherds and teachers, (12) to equip the saints for the work of ministry, for building up the body of Christ, (13) until we all attain to the unity of the faith and of the knowledge of the Son of God, to mature manhood, to the measure of the stature of the fullness of Christ
1Corinthians 2:4-5 and my speech and my message were not in plausible words of wisdom, but in demonstration of the Spirit and of power, (5) that your faith might not rest in the wisdom of men but in the power of God.
Matthew 24:14 And this gospel of the kingdom shall be proclaimed in all the world as a witness to all nations. And then the end shall come.
The purpose of God is to have sons like Jesus who will manifest His glory to the whole world and destroy the works of Satan:
John 14:12 “Truly, truly, I say to you, whoever believes in me will also do the works that I do; and greater works than these will he do, because I am going to the Father.
Isaiah 40:5 And the glory of the LORD shall be revealed, and all flesh shall see it together, for the mouth of the LORD has spoken.”
1John 3:8 He that committeth sin is of the devil; for the devil sinneth from the beginning. For this purpose the Son of God was manifested, that he might destroy the works of the devil.
Romans 8:19 For the earnest expectation of the creation waits for the manifestation of the sons of God.
In the natural, we know that we have great joy when a baby is born, however if after some years the child begins to show a lack of development both mentally and physically, the same child now becomes a source of sorrow and concern for the parents: it is no different with God.
After years of being born-again if we still have the same level of wisdom and spiritual capacity as babies or little children then we will not be satisfying God:
Hebrews 5:12-14 For though by this time you ought to be teachers, you need someone to teach you again the basic principles of the oracles of God. You need milk, not solid food, (13) for everyone who lives on milk is unskilled in the word of righteousness, since he is a child. (14) But solid food is for the mature, for those who have their powers of discernment trained by constant practice to distinguish good from evil.
How then do we grow from being children of God to becoming Sons of God?
By speaking the truth: God’s Word (Jn. 17.17) in love to perfect the love of God in our lives by the blood, the Word and the power of the Holy Spirit:
We clean our hearts frequently with blood of Jesus by confessing our sins and washing one another’s feet spiritually (Jn. 13.14,15,34 and 1 Jn. 1.7-10):
Heb 13:20-21 Now may the God of peace who brought again from the dead our Lord Jesus, the great shepherd of the sheep, by the blood of the eternal covenant, (21) equip you with everything good that you may do his will, working in us that which is pleasing in his sight, through Jesus Christ, to whom be glory forever and ever. Amen.
We speak God’s Word on the love of God (1 Cor. 13.4-8) in faith ( Rom. 4.17) as a daily habit to create in our souls and bodies the character of love:
1John 2:5 but whoever keeps his word, in him truly the love of God is perfected. By this we may know that we are in him:
We pray with tongues (1 Cor. 14.4) and groanings (Rom. 8.26, Heb 5.7) to release the power of the Holy Spirit to act on the spoken Word (Gen. 1.2-3) to cause the Christ nature and power to be permanently formed in our souls and bodies:
Galatians 4:19 My children, for whom I again travail until Christ should be formed in you,
Ephesians 3:16-19 that He would grant you, according to the riches of His glory, to be strengthened with might by His Spirit in the inner man; (17) that Christ may dwell in your hearts by faith; that you, being rooted and grounded in love, (18) may be able to comprehend with all saints what is the breadth and length and depth and height, (19) and to know the love of Christ which passes knowledge, that you might be filled with all the fullness of God.