6 Therefore since it still remains for some to enter that rest, and since those who formerly had the good news proclaimed to them did not go in because of their disobedience,

Read Hebrews 4:6 Using Other Translations

Seeing therefore it remaineth that some must enter therein, and they to whom it was first preached entered not in because of unbelief:
Since therefore it remains for some to enter it, and those who formerly received the good news failed to enter because of disobedience,
So God’s rest is there for people to enter, but those who first heard this good news failed to enter because they disobeyed God.