Mat 26:28 For this is my blood of the new testament, which is shed for many for the remission of sins.
Strong's Greek Word Testament
From G1303; properly a disposition, that is, (specifically) a contract (especially a devisory will): - covenant, testament.
Noun 1. devisor - someone who devises real property in a will
testate, testator - a person who makes a will
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.
Rom 5:6 For when we were yet without strength, in due time Christ died for the ungodly.
Rom 5:7 For scarcely for a righteous man will one die: yet peradventure for a good man some would even dare to die.
Rom 5:8 But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us.
Rom 5:9 Much more then, being now justified by his blood, we shall be saved from wrath through him.
Rom 5:10 For if, when we were enemies, we were reconciled to God by the death of his Son, much more, being reconciled, we shall be saved by his life.
Heb 10:19 Having therefore, brethren, boldness to enter into the holiest by the blood of Jesus,
Heb 10:20 By a new and living way, which he hath consecrated for us, through the veil, that is to say, his flesh;
Gen 15:17 And it came to pass, that, when the sun went down, and it was dark, behold a smoking furnace, and a burning lamp that passed between those pieces.
Gen 15:18 In the same day the LORD made a covenant with Abram, saying, Unto thy seed have I given this land, from the river of Egypt unto the great river, the river Euphrates:
Heb 11:17 By faith Abraham, when he was tried, offered up Isaac: and he that had received the promises offered up his only begotten son,
Heb 11:18 Of whom it was said, That in Isaac shall thy seed be called:
Heb 11:19 Accounting that God was able to raise him up, even from the dead; from whence also he received him in a figure.
Yes Christ the testator did die to enact the New Will and Testament which brought us into the Kingdom of God. The word testament was used by Christ to describe his act of sacrifice for our sins. Strongs greek word for testament it specifically says the original word was a devisory will. I included the definition for devisory incase that word is unfamiliar. The Old covenant was a covenant established through the death of animals because of the willingness of Abraham to offer Isaac. There are no testators of the old covenant only partners.
I disagree with the other answer posted because it disagrees with Jesus and the writers of Hebrews 9 and offers a theological answer which does not properly reflect the words of Jesus nor the tone of the Bible.