First, at no time is a sinner duty-bound under both covenants simultaneously.
Second, so long as the sinner remains unregenerate, he/she is held accountable under the terms and promises of the Covenant of Works (not the Covenant of Grace).
Third, once the sinner has been born again, he/she is delivered/released from the Covenant of Works, being brought experientially under the terms and promises of the Covenant of Grace.
Fourth, the non-elect have absolutely no part in the Covenant of Grace—it is not their duty to believe savingly on Christ, nor is it the duty of the preacher to offer…