now, if the Spirit puts to death the deeds of the flesh we will live, for those led by the Spirit exist the sons of God (Romans 8:12)
Children have testimony of the Spirit, that they exist a child of of God. But a son has grown into maturity, being led by the Spirit to put to death the deeds of the flesh. Paul wrote earlier in this letter, "knowing this, because our old self was crucified with him, so that the body of sin would be rendered useless..." (Romans 6:6). These are teachings of baptism that those who follow Christ should commit to (Romans 6:17). Dying to the old self and the Spirit putting to death the deeds of the flesh are equivalent and seen in the difference of maturity between a child and young person. It is also explained as transformation, the old is transformed into the new, Paul writing this our reasonable service and acceptable sacrifice to God where we present the body, the old self, a living sacrifice (Romans 12:1-2).
John speaks of the difference of maturity, "my children I write these things so you may not sin" and "whoever keeps his word truly in them the love of God is perfected" and "I am writing to you children because your sins are forgiven... and you know the Father" and "I am writing to you young person because you are strong... the word of God abides in you... and you have overcome the evil one" (1 John 2).
and if children (teknon) then heirs, heirs of God together with Christ, provided we suffer with him so also to be glorified with him (Romans 8:17)
God predestined us as his own, as children of God, adopting us of his Spirit (Ephesians 1:5). In which we become co-heirs with Christ, who became like his brethren in the flesh, so to give us the right to become children. As children (teknon) the Spirit testifies that we are his own (Romans 8:16) and so does the blood of the new covenant. As sons (hyios) the water testifies, seen in the teachings of baptism, that the old man has been crucified with Christ, dead to sin and made alive to God. The testimony is in the experiential knowing of the truth that sets one free.
The water is not a testimony of the washing of dirt from the body but of a good conscious toward God (1 Peter 3:21) in that we are indebted as children to grow up and bear fruit of righteousness. To live according to our new nature, and if we do not we will not have a good conscious toward God. It is a testimony of becoming a son, having died and been buried with him, conformed to his death, having fellowship in his suffering, sin rendered useless. A son comes into existence alive to God, led by the Spirit to put to death the deeds of the flesh, walking in step with the Spirit of truth, walking in newness of life. A son is strong because the word of God abides in him as the Spirit has led and guided him into this truth, to abide in him whose words exist truth, life, and the way to freedom.
that the creation itself will be set free from its bondage to decay into the glorious freedom of the children (teknon) of God... (Romans 8:21-24)
Creation itself has been groaning and suffering up until this hour and we ourselves who have the first fruits of the Spirit grown inwardly awaiting our adoption, the redemption of our body. This is the battle, victorious, but not yet. Christ has been placed over all things, but it is clear not all things have yet been placed under his feet, the final thing to be place under his feet being death (Ephesians 1:22; 1 Corinthians 15:19-29).
The gospel is one in which we are saved and being saved (1 Corinthians 15:1-2). And of one that states one day we will be saved as we await our Saviors return, we await the fullness of our salvation, a body without decay, corruption, and sin. So we fight the good fight, run the race set before us in order to receive the prize, becoming a son receiving our inheritance the crown of life, the gain of knowing Christ and his life. We do so because Christ has laid hold of us, urging us on because we are his own.
My little children (teknon) for whom I am again in the pain of childbirth until Christ is formed in you, (Galatians 4:19)
Being a new creation in Christ we await the glorious freedom as children of God. We await the fullness of our inheritance as sons of God, in which the Spirit is a guarantor of the redemption of his own (Ephesians 1:14). The Spirit interceding, groaning to deep for words inwardly in our weakness... as we are becoming sons being formed into our true identity, into the image of his Son.