To say "unbelievers" refuse to accept the covenant misses the point that the covenant promise is only made to "believers." There is no promise to save those who do not believe. The gospel finds unbelievers condemned already, and where the gospel is not believed it leaves its hearers in the same state in which it found them -- under the condemnation of the law.
There are two covenants as there are two Adams. Every man is either condemned under the first Adam or saved under the second Adam.
There are two covenants as there are two Adams. Every man is either condemned under the first Adam or saved under the second Adam.