“For unto us was the gospel preached, as well as unto them: but the word preached did not profit them, not being mixed with faith in them that heard it.”
King James Version (KJV)
4:2 But the word which they heard did not profit them - So far from it, that it increased their damnation. It is then only when it is mixed with faith, that it exerts its saving power.
Heb 4:2 For unto us was the gospel preached, as well as unto them. We have the promises of the gospel, but they had the promises of an earthly land of rest preached to them. They broke the covenant on which the promises were based. The word which they heard did not profit them. The reason was that it was not received in unfaltering faith. Hence they did not obey it. So unbelief would make the gospel to us of none effect.