New Covenant Established
At the death of the Testator (our Lord Jesus), He abolished the Law and out of His grace He established the New Covenant of His blood for all men starting with the Jews.
All believers (born again Christians) immediately can fellowship with God, set free from bondages and are now children of God just like Adam.
Gal 5:1 Stand fast therefore in the liberty by which Christ has made us free, and do not be entangled again with a yoke of bondage.
First Sin Leading to Death
Gen 2:16-17 And the Lord God commanded the man, saying, "Of every tree of the garden you may freely eat; but of the tree of the knowledge of good and evil you shall not eat, for in the day that you eat of it you shall surely die."
By God's grace, Adam was created to be His son and was free to eat everything in the garden of Eden except for the fruit from the tree of the knowledge of good and evil.
When Adam rebelled against His command and ate the fruit, he fell out of God's grace. The Lord then chased him out from the garden of Eden so that he could no longer partake from the tree of life resulting to his eventual death (lost of salvation).
Idolatry - Sin Leading to Death
1 John 5:16 If anyone sees his brother sinning a sin which does not lead to death, he will ask, and He will give him life for those who commit sin not leading to death. There is sin leading to death. I do not say that he should pray about that.
Whenever a Christian sins and if he repents and confesses his sin, the blood of Jesus will cleanse him of his sin. Out of His great love, this is His grace to us.
Though by grace we are saved there are sins leading to death that we must avoid. So just like Adam, if we rebel by committing these sins leading to death, we too will fall out of His grace and lose our salvation (e.g. Idolatry)
1 John 5:21 Little children, keep yourselves from idols. Amen.
Falling Out of Grace
Gal 5:4 You have become estranged from Christ, you who attempt to be justified by law; you have fallen from grace.
Any Christian (including Jewish converts) who practices any part of the Law, which is another sin leading to death will no longer be in the grace of God for he had lost his salvation by rebelling against His command.
Gal 3:10 For as many as are of the works of the law are under the curse; for it is written, "Cursed is everyone who does not continue in all things which are written in the book of the law, to do them."
Synagogue of Satan
Rev 2:8-9 "And to the angel of the church in Smyrna write, 'These things says the First and the Last, who was dead, and came to life: I know your works, tribulation, and poverty (but you are rich); and I know the blasphemy of those who say they are Jews and are not, but are a synagogue of Satan."
These so-called Christians in the church of Smyrna think that they are holier if they are more Jewish. So they introduce the obsolete Law into their belief, prayer or worship, making the church the synagogue of Satan.
They are forcing our Lord Jesus Christ living within us to submit to the weak Mosiac Law. This type of blasphemous services, sacrifices and worships is another sin leading to death.
Gal 2:19-20 For I through the law died to the law that I might live to God. I have been crucified with Christ; it is no longer I who live, but Christ lives in me; and the life which I now live in the flesh I live by faith in the Son of God, who loved me and gave Himself for me.