if the burden of our sin could destroy our Saviour then there is no such thing as salvation -- but He is declared Priest by the power of an indestructible life!
no one takes His life - He lays it down and He takes it up again.
Jesus voluntarily placed Himself as our High Priest and Sacrificial Lamb. Yes, He laid down His life but He didn't kill Himself. He "gave up the ghost, and died". Others were to a point culpable. Paul and Stephen correctly called the Jews murderers. The Romans themselves "knew not what they were doing", so Jesus wasn't holding them responsible. The leaders of Israel who had all the evidence that Jesus was truly the Messiah, but resisted all their convictions to the truth, were all guilty of the unpardonable sin... Blaspheming the holy Spirit.
But what was in reality the cause of the death of the Son of God? Us. We are. Every time we sin we crucify Him afresh. Every time we disobey God we add to the burden that was placed upon Christ at Calvary. How that works on God's time I don't know. But somehow it is necessary because without the shedding of blood there is no remission. And only someone equal to the law can atone for it's transgression. As giver of the law, the Son was fully qualified to pay the redemption price for mankind. That price was death. Christ fully and completely died, not just as a man, but as the Son of God manifested in the flesh, full of grace, truth, and all the attributes of the Godhead bodily, suffered complete and utter separation from God having no hope at the point of death of a resurrection. How could He? Was it not our death, the final second death that has no resurrection and no hope, that He accepted in our place? Anything short of that and the propitiation is incomplete.
And another thing. It was always a possibility that Christ could have sinned, and this was a risk that both Father and Son were willing to make for our sake. Christ considered eternal life with His Father not worth having if it were at our expense. What love! What condescension! What grace, mercy, and faithfulness the Father and Son have toward sinful man!!
KJV 1 John 4:9-10, 14-15
9 In this was manifested the love of God toward us, because that God sent his only begotten Son into the world, that we might live through him.
10 Herein is love, not that we loved God, but that he loved us, and sent his Son to be the propitiation for our sins.
14 And we have seen and do testify that the Father sent the Son to be the Saviour of the world.
15 Whosoever shall confess that Jesus is the Son of God, God dwelleth in him, and he in God.
KJV 1 John 3:16
16 Hereby perceive we the love of God, because he laid down his life for us: and we ought to lay down our lives for the brethren.
KJV 1 John 5:11-13
11 And this is the record, that God hath given to us eternal life, and this life is in his Son.
12 He that hath the Son hath life; and he that hath not the Son of God hath not life.
13 These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God.