Romans 6:
Philippians 2
We all sin. We all die according to God's law. So, we need atonement, Leviticus 17:23 the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.
Jesus knew it, Luke 18:11 For the life of the flesh is in the blood, and I have given it for you on the altar to make atonement for your souls, for it is the blood that makes atonement by the life.
Jesus said it was necessary, Luke 24:31 Then Jesus took the Twelve aside and said to them, “Look, we are going up to Jerusalem, and everything the prophets have written about the Son of Man will be fulfilled. 32 He will be delivered over to the Gentiles and will be mocked and insulted and spit upon. 33 They will flog Him and kill Him, and on the third day He will rise again.”
Paul explained in Hebrews 10:25 he said to them, “O foolish ones, and slow of heart to believe all that the prophets have spoken! 26 Was it not necessary that the Christ should suffer these things and enter into his glory?” 27 And beginning with Moses and all the Prophets, he interpreted to them in all the Scriptures the things concerning himself.
It was the will of God that Christ should die.4 For it is impossible for the blood of bulls and goats to take away sins. 5 Consequently, when Christ came into the world, he said,
“Sacrifices and offerings you have not desired,
but a body have you prepared for me;
6in burnt offerings and sin offerings
you have taken no pleasure.
7Then I said, ‘Behold, I have come to do your will, O God,
Jesus was the perfect sacrifice who died for us according to the will of God.as it is written of me in the scroll of the book.’” ...
10 And by that will we have been sanctified through the offering of the body of Jesus Christ once for all.
Philippians 2
As a result:8 And being found in human form, he humbled himself by becoming obedient to the point of death, even death on a cross.
Amen.9 Therefore God has highly exalted him and bestowed on him the name that is above every name, 10so that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, 11and every tongue confess that Jesus Christ is Lord, to the glory of God the Father.