A Christian can be cut off from Christ. Paul says to the Christians in Galatia who are being deceived and bewitched to go back to the Old Law. He says to them, “You have been severed from Christ,…” Gal. 6:4.
Paul went to great lengths to show the Christians there is no justification in keeping the Old Law, “Now that no one is justified by the Law before God is evident; for, ‘The righteous man shall live by faith’“, Gal 3:11. And, “We are Jews by nature and not sinners from among the Gentiles; nevertheless knowing that a man is not justified by the works of the Law but through faith in Christ Jesus, even we have believed in Christ Jesus, so that we may be justified by faith in Christ and not by the works of the Law; since by the works of the Law no flesh will be justified“, Gal 2:15,16. Paul even went on to show how Peter stood condemned because he withdrew from the Gentiles in order to please the Jews, Gal. 2:11,12. These Galatians were in jeopardy of losing their salvation by turning back to the Old Law. Those who turn back to the Old Testament law and worship would be severed from Christ.
So Paul says to some Christians, “you have been severed from Christ.” There’s no way to read that except with the understanding that Christians can lose their salvation.
To some people this news is a little shocking because they have been deceived to believe that a Christian cannot lose his salvation. They turn to passages like, Romans 8:38,39 and John 10:28. Though these passages give comfort and confidence of the security we have with Christ, they do not say that the sheep cannot themselves stray nor that we cannot separate ourselves from God’s love.
Admittedly, this knowledge can be disconcerting to someone who has been raised to believe the doctrine of “eternal security”, or in Calvin’s terms, “perseverance of the saints.” And in fact it is hard to lose your salvation. 1 John 1:6ff shows that God is light and if Christians walk in the light, two things: 1] they are not going to be perfect, and 2] the blood of Jesus continually cleanses them from the sins they will commit. So imperfect people are going to be saved. The Christian that loses his salvation is the one who has decided not to walk in the light of grace by faith. To lose your salvation requires a wholesale turning away from trusting in Christ to doing something like turning to the Old Law or a different Gospel, Gal. 1:6-9.
I don’t write this to trouble anyone. In fact it should be comforting to know that the God of patience is loving and forgiving to imperfect Christians. But we should also be aware that we can fall from saving grace, Gal. 5:4. So keep your faith in the atoning work of Christ. And obey Him with all of your heart and you will be saved.