Galatians 5:4-6: "You have become estranged from Christ, you who attempt to be justified by law; you have fallen from grace.
For we (believers) through the Spirit eagerly wait for the hope of righteousness by faith. For in Christ Jesus neither circumcision nor uncircumcision avails anything, but faith working through love"
No mention here of believers falling from grace, or losing salvation.
It mentions "you" versus "we".
V1 addresses non believers who are trying to be saved by law (works). Since they're seeking salvation (the wrong way), evidently they don't yet have it. Paul says that they are the ones that have fallen from grace. Many were trying to add to the finished work of Jesus, making additional requirements for salvation, such as circumcision.
So based on these facts it's clear that "fallen from grace" means that they fall away from grace. They reject the gospel of grace, instead believing their works are necessary, when it is Christ's work alone and nothing added.
To add to my post.....
Galatians 3 shows believers trying to be sanctified by the flesh
Galatians 5 shows non believers trying to be justified by the flesh
Galatians 3:1-9: "O foolish Galatians! Who has bewitched you that you should not obey the truth, before whose eyes Jesus Christ was clearly portrayed among you as crucified? This only I want to learn from you: Did you receive the Spirit by the works of the law, or by the hearing of faith? Are you so foolish?
Having begun in the Spirit (believers), are you now
being made perfect (sanctified) by the flesh? Have you suffered so many things in vain—if indeed it was in vain?
Therefore He who supplies the Spirit to you and works miracles among you, does He do it by the works of the law, or by the hearing of faith?— just as Abraham “believed God, and it was accounted to him for righteousness.” Therefore know that only those who are of faith are sons of Abraham. And the Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel to Abraham beforehand, saying, “In you all the nations shall be blessed.” So then those who are of faith are blessed with believing Abraham"
Galatians 5:1-6: "
(Believers) Stand fast therefore in the liberty by which Christ has made us free, and do not be
entangled again with a yoke of
bondage. Indeed I, Paul, say to you that if you become circumcised, Christ will profit you nothing. And I testify again to every man who becomes circumcised that he is a debtor to keep the whole law.
You (non believers) have become estranged from Christ,
you who attempt to be justified by law; you have fallen
from grace.
For we (because we) through the Spirit (believers) eagerly wait for the hope of righteousness by faith. For in Christ Jesus neither circumcision nor uncircumcision avails anything, but faith working through love"
In Galatians 3 they have begun in the Spirit (so they are born again believers) but they are trying to
maintain their salvation themselves.
In Galatians 5 clearly being addressed are non believers, because they are trying to be
justified by the flesh. Then the distinction is made "FOR WE (because we) through the Spirit" which speaks of believers, so a distinction is made.
"Fallen from grace" does not suggest losing salvation, since the context here is non believers who are trying to be justified by the law, so they are not saved to begin with, they are "attempting" to be saved.
Believers who are trying to maintain their salvation (claiming that salvation is conditional, that it can be lost, and that we must maintain it ourselves).... the message given is to not become
entangled again with the yoke of bondage, which you have been freed from. You will lose your joy because you're not resting in what Christ has done for you. You will become entangled in the burdens that the lost are burdened with.
Why become entangled again?!