Jesus Christ willingly layed down His life as a man in order to pay the penalty for our sins on the cross so that we could be forgiven for our transgressions against a Holy God. You see there is a penalty which must bee paid for breaking God’s Law’s or commandments, what the Bible call’s sinning, and that penalty is death.
We are not speaking of a physical death but a spiritual one which means spending eternity in Hell separated from God and not merely ceasing to exist. So because of His great Love for us God willingly came to the earth and clothed Himself with human flesh and was born as a man so that He could pay the penalty for our sins on the cross, satisfying the requirements of His Law, enabling Him to forgive those who trust in Jesus Christ and satisfy the requirements of His Law’. So it was Jesus Christ in the flesh who died on the Cross as a man and not as God. And even though Jesus died on the Cross does not mean He ceased to exist!
And as Moses lifted up the serpent in the wilderness, even so must the Son of man be lifted up: (Joh 3:14)
That whosoever believeth in him should not perish, but have eternal life. (Joh 3:15)
For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. (Joh 3:16)
For God sent not his Son into the world to condemn the world; but that the world through him might be saved. (Joh 3:17)
He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God. (Joh 3:18)