Repeating the same nonsense over and over will never make it true. Heb 6:4-6 lists profound religious experiences. But a person can experience the outward blessings, community, and truth of the gospel without being truly saved.
Note what the author of Hebrews says in verse 9, "Though we speak in this way, yet in your case, beloved, we feel sure of better things—things that belong to salvation." This shows the writer is separating true believers from your hypothetical group.
God preserves those He truly saves. Scripture teaches that genuine believers cannot be snatched from Christ's hand. If someone completely turns away from Christ (apostasy), it proves they never possessed true saving faith to begin with.
Galatians 5:4 exposes you Arminian "saved by works" version of the gospel as being false. Paul uses strong rhetorical warnings to shake people out of your legalism, contrasting the two mutually exclusive paths of grace versus law.
God said "we are saved by grace", but you say no "we are saved by faith". So you reject Gods grace, and forget that faith is entirely a gift from God rather than a humanly generated work or ability. You make your faith a work, to earn salvation. That's pure Arminianism
Repeating nonsense does not make it true, but meditating on Scripture you ignore might be enlightening.
If the writer of Hebrews thought apostates could only be a hypothetical group, then he would not have wasted
so much ink warning against apostasy. The possible groups include:
a. normally loving people who have rare moments when they act uncharacteristically (Phil. 3:12-16)
b. immature Believers, who are making progress–you should have known them a year ago! (1Cor. 3:1-3, Eph. 4:11-15)
c. truthseekers who have not yet learned the correct interpretation of God’s Word (1Cor. 6:9-11, Eph. 5:8-9)
d. pseudo-Christians (Matt. 7:21, 1John 2:19), who affirm Jesus as Messiah but rejects His Lordship
e. apostates or heretics (1John 2:19, Heb. 6:4-6), who once believed but became blasphemous or foolish and ship-wrecked their faith (1Tim. 1:19-20).
f. atheists, who may imitate divine love without glorifying the One whose power makes it a golden rule rather than merely a pyrite suggestion.
Regarding faith, the crucial point is that God will not force sinners to receive His gift of salvation;
they must satisfy His condition of faith through wanting to have it.
God initiates/offers/gives; sinners may cooperate/accept/receive--or not.