I get what you mean, but Christ needed to be crucified, buried, resurrected, and ascended back to the Father in heaven in order to initiate the new testament or the new covenant.
Heb 9:11
But Christ being come an high priest of good things to come, by a greater and more perfect tabernacle, not made with hands, that is to say, not of this building;
Heb 9:12
Neither by the blood of goats and calves, but by his own blood he entered in once into the holy place, having obtained eternal redemption for us.
Heb 9:13
For if the blood of bulls and of goats, and the ashes of an heifer sprinkling the unclean, sanctifieth to the purifying of the flesh:
Heb 9:14
How much more shall the blood of Christ, who through the eternal Spirit offered himself without spot to God, purge your conscience from dead works to serve the living God?
Heb 9:15
And for this cause he is the mediator of the new testament, that by means of death, for the redemption of the transgressions that were under the first testament, they which are called might receive the promise of eternal inheritance.
Heb 9:16
For where a testament is, there must also of necessity be the death of the testator.
Heb 9:17
For a testament is of force after men are dead: otherwise it is of no strength at all while the testator liveth.
A testament goes into effect or is of force after men are dead, and it is of no strength at all while the testator is yet alive. It is by means of death, for the redemption of the transgressions that were under the first testament or the old testament, that we which are called can receive the promise of eternal inheritance. Christ not only needed to die and be resurrected, but he also needed to enter into the true holy place in heaven by his own blood in order to obtain redemption for us, and he did this when he ascended back to the Father in heaven. There is no remission of sins without the shedding of blood.
Heb 9:22
And almost all things are by the law purged with blood; and
without shedding of blood is no remission.
The blood that redeems us was shed on the cross, and not in the garden of Gethsemane.
Col 1:20
And,
having made peace through the blood of his cross, by him to reconcile all things unto himself; by him,
I say, whether
they be things in earth, or things in heaven.
Col 1:21
And you, that were sometime alienated and enemies in
your mind by wicked works, yet now
hath he reconciled
Col 1:22
In the body of his flesh through death, to present you holy and unblameable and unreproveable in his sight:
Furthermore, it was not until the time of Christ's glorification that he was "appointed heir of all things" (Heb. 1:2), so none of us could possibly become "joint-heirs with Christ" (Rom. 8:17) without this aspect of Christ's redemptive work.
Under the old testament, the saints who looked forward to this complete redemptive work of Christ by faith had righteousness imputed unto them. Whereas they looked forward to it by faith, under the new testament, we look back upon it by faith.