"4But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law, 5To redeem them that were under the law, that we might receive the adoption of sons. 6And because ye are sons, God hath sent forth the Spirit of his Son into your hearts, crying, Abba, Father. 7Wherefore thou art no more a servant, but a son; and if a son, then an heir of God through Christ." (Galatians 4: 4-7)
Jesus did died on the Cross for our sins, but for so much more:
"12Therefore, brethren, we are debtors, not to the flesh, to live after the flesh. 13For if ye live after the flesh, ye shall die: but if ye through the Spirit do mortify the deeds of the body, ye shall live. 14For as many as are led by the Spirit of God, they are the sons of God. 15For ye have not received the spirit of bondage again to fear; but ye have received the Spirit of adoption, whereby we cry, Abba, Father." (Romans 8: 12-15)
The Gospel is more than "He died for my sins". God justifies us before Himself through His Son:
"38Be it known unto you therefore, men and brethren, that through this man is preached unto you the forgiveness of sins: 39And by him all that believe are justified from all things, from which ye could not be justified by the law of Moses." (Acts 12: 38-39)
We are no longer under law, but now under grace:
"For sin shall not have dominion over you: for ye are not under the law, but under grace." (Romans 6: 14)
"15What then? shall we sin, because we are not under the law, but under grace? God forbid. 16Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness?" (Romans 6: 15-16)
Paul emphasizes that we are freed from the law:
"4Wherefore, my brethren, ye also are become dead to the law by the body of Christ; that ye should be married to another, even to him who is raised from the dead, that we should bring forth fruit unto God. 5For when we were in the flesh, the motions of sins, which were by the law, did work in our members to bring forth fruit unto death. 6But now we are delivered from the law, that being dead wherein we were held; that we should serve in newness of spirit, and not in the oldness of the letter." (Romans 7: 4-6)
So, we are no longer under law, but under grace, and in this grace we grow in knowledge of the Lord, and we liv godly lives:
"But grow in grace, and in the knowledge of our Lord and Saviour Jesus Christ. To him be glory both now and for ever. Amen." (2 Peter 3: 18)
"11For the grace of God that bringeth salvation hath appeared to all men, 12Teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly, in this present world; 13Looking for that blessed hope, and the glorious appearing of the great God and our Saviour Jesus Christ; 14Who gave himself for us, that he might redeem us from all iniquity, and purify unto himself a peculiar people, zealous of good works." (Titus 2: 11-14)
Grace is the teacher we need, not law:
"5And ye have forgotten the exhortation which speaketh unto you as unto children, My son, despise not thou the chastening of the Lord, nor faint when thou art rebuked of him:
6For whom the Lord loveth he chasteneth, and scourgeth every son whom he receiveth.
7If ye endure chastening, God dealeth with you as with sons; for what son is he whom the father chasteneth not." (Hebrews 12: 5-7)
Grace is the teacher, which we see in Christ, which makes less of ourselves and more of Himself. The more that we see how favored we are in Christ (Ephesians 1: 6), that as He is, so are we in this world (1 John 4: 17), then we deny, reject, throw away ungodliness and worldly (finite, unfulfilling) desires.
Consider also this exhortation from the Psalms:
"Be ye not as the horse, or as the mule, which have no understanding: whose mouth must be held in with bit and bridle, lest they come near unto thee." (Psalm 32: 9)
God calls us to better than an animal life. He does not want to drive us from the outside, but motivate us from within:
"Many sorrows shall be to the wicked: but he that trusteth in the LORD, mercy shall compass him about." (Psalms 32: 10)
The LORD is interested in mercy/grace (chesed) surrounding us, and He is interested in our trusting in Him, depending on Him for all things.
"Be glad in the LORD, and rejoice, ye righteous: and shout for joy, all ye that are upright in heart." (Psalm 32: 11)
Growing as sons of God is not about what we do, but seeing all that He is doing, and rejoicing in all that He has done for us. Love perfected means that we identify with Christ Jesus.
We cannot identify with him in ourselves, through our flesh.
For sons, it's not about the law, which causes sin to increase (Romans 5: 20), which is the strength of sin (1 Corinthians 15: 56-57).
To grow in Christ, we grow in grace, receiving all things from Him, as God our Daddy has promised:
"31What shall we then say to these things? If God be for us, who can be against us? 32He that spared not his own Son, but delivered him up for us all, how shall he not with him also freely give us all things? 33Who shall lay any thing to the charge of God's elect? It is God that justifieth. 34Who is he that condemneth? It is Christ that died, yea rather, that is risen again, who is even at the right hand of God, who also maketh intercession for us." (Romans 8: 31-34)