Born under the Old Covenant, Christ was personally and perfectly obedient, satisfying strict justice and thus Himself being declared justified. Whereas, the New Covenant context is one of our being declared justified on the sole basis of His righteousness. By this means we are permitted to both enter and remain in the Land of Promise; again, on the sole basis of His obedience.
Therefore, we aren’t being brought merely ‘back to Eden’ to attempt to do what the first Adam did not, nor are we striving like Israel to keep the Law in order to remain in the promised land. All conditions of this New Covenant are met in Christ, making our involvement in the Kingdom all of grace.
We have come to Mt. Zion, where we boldly approach the throne of grace, upon which a slain Lamb resides! With Him we are now seated, having been legally accredited (imputed) with His righteousness, thus being heirs with Christ’s present and everlasting reign.