Therefore, this is because certain ones remain who are to enter into it, and those to whom it was announced first did not enter into it, because of unbelief
Other versions
King James Version
Seeing therefore it remaineth that some must enter therein, and they to whom it was first preached entered not in because of unbelief: English Standard Version
Since therefore it remains for some to enter it, and those who formerly received the good news failed to enter because of disobedience,New International Version
It still remains that some will enter that rest, and those who formerly had the gospel preached to them did not go in, because of their disobedience.