A Christian CANNOT become an accursed child. Not possible. God does not allow His children to be cursed. God is sovereign. No one has the power to curse one whom God has decided to bless. God is the only One able to pronounce judgment.
Those who do not love the Lord are accursed. The Apostle Paul wrote in I Corinthians 16:22,“If anyone does not love the Lord Jesus Christ, let him be accursed.”
Does a Christian, a saved person, a born again believer love the Lord Jesus Christ? Yes or No?
Hebrews 10:38-39 is speaking to saved Jews. Verse "But we are not of them who draw back unto perdition; but of them that believe to the saving of the soul." (Hebrews 10:39) Those that "turned back into perdition were the Jew who professed Jesus Christ as Savior, but who were never saved. The Book of Hebrews was written to "Hebrews" as its title states. Many who had professed faith in Jesus Christ were looking for the Messiah to come and liberate them from the Romans and the persecution they were enduring. They had a false concept of who Jesus is and what He came to do. He did not come a a political leader, but as the Savior who died for the sins of the world. He came to redeem men from sin. Yes, in time He will fulfill the promises God has made to Israel, but only those who will be a part of that Kingdom (Millennial Kingdom) are those who are spiritually reborn in Jesus Christ. Saved people do not draw back into perdition. Hebrews 12:6-11 explains that the true child of God who turns from the truth and goes into sin will be chastened by the Lord. God says He chasten "every" child of His who goes into sin and refuses to repent. NEVER, DOES GOD SAY HE WILL WITHDRAW THEIR SALVATION. NEVER! In 1 Corinthians 11:29-30 explains that God chasten with sickness and death those who do not "discern" the body of Christ. That means those who live sinful lives not mindful that Jesus had to suffer for our every sin. 1 John 5:16-18 explains there is a sin unto death. God will take the life of a believer who refuses to repent and turn from their sin. 1 Corinthians 3:10-15 explains that a believer is saved, but if he does not live a godly life can lose any reward. He gets into heaven "as by fire" meaning by the skin of his teeth in a modern expression. This passage does not teach a saved person can be lost.
In a nut shell the answer to your question is that once a person believes they receive "eternal or everlasting" salvation. As 1 Peter 1:3-5 states we are kept by the power of God and as Jesus stated, "And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand." (John 10:28)
God will not force anyone to stay in the family of God.
Didn't the Apostle Peter turn back just briefly when he denied Christ???