'Christ Died For The Ungodly'

How could Jesus die? He was the sinless Son of God, Child of the Holy Ghost! (Matthew 1:18)

Jesus was God, the Word, Who came down from Jesus' Father's throne, and was conceived in a virgin by God, the Holy Ghost (Matthew 1:18), entering into a body of sinless flesh (for He was not born of Adam's sinful flesh: II Corinthians 5:21; Galatians 4:4; John 1:1-14; Hebrews 10:1-5), that He might walk among men, as God spoke to Moses (Deuteronomy 18:18-19); and those men to whom Jesus was specifically sent were only the the Jews of Israel, descendants of Abraham, the father of our faith through Jesus Christ our Lord.

They were the people of the covenant by circumcision.
So, since Jesus was not born with the curse of Adam, how could Jesus die?

Jesus had to be sinless to fulfil His purpose, to be the only Savior by Whom men might come to God, by believing in the only begotten Son of God (Jehovah/Yahweh, more commonly known).

Jesus had no sin as from Adam's sinful flesh, neither did He err in keeping the law of Moses.
 
So when Christ Jesus our Lord was on the cross, being crucified by those to whom He came, He took on all of the sins of the whole world, .

And therefore, being our 'sin-bearer', when He took all of the sins of the whole world, from Adam to the last conceived child, He became guilty of all of our sins, the sins of all of humanity, and of the whole world.

God, the Word did not die, just as, when we die, only our flesh dies; however our soul is eternal; therefore it never sleeps, neither does it cease to exist, nor can it die. And therefore, God, the Word, the Spirit of Christ could not die.
But while Jesus was lying dead in the grave, God, the Word, went and preached unto the spirits that were in 'prison', in Abraham's nearness (bosom), as is detailed in I Peter 3:18-20, and then 'led captivity captive' into the presence of God, being transformed by the word of God, believing in Jesus.