Good important question: How can our own sinning make us guilty of wrongly smiting Jesus' body on a cross? Afterall, we were not there.What is the process by which man places their sins onto Jesus?
Because all sin is committed against Christ, and not only against man.
Psa 51:3
For I acknowledge my transgressions: and my sin is ever before me. Against thee, thee only, have I sinned, and done this evil in thy sight: that thou mightest be justified when thou speakest, and be clear when thou judgest.
Not only the hands of His slayers were wicked, but also the hands of all men that sin against Christ. For Christ must come to die for the sins of all men, the Jew first and also the Gentile.
The offense of the cross, is not only that Jesus Christ the righteous was beaten and crucified by wicked hands, but that all we who have sinned against Him, are likewise made guilty of shedding His innocent blood.
Mat 27:25
Then answered all the people, and said, His blood be on us, and on our children.
Act 5:27
And when they had brought them, they set them before the council: and the high priest asked them, Saying, Did not we straitly command you that ye should not teach in this name? and, behold, ye have filled Jerusalem with your doctrine, and intend to bring this man's blood upon us....
Jesus was not imputed with any sin on the cross, for He knew no sin. All men that sin are imputed with crucifying Him to a cross.
Heb 6:6
Seeing they crucify to themselves the Son of God afresh, and put him to an open shame.
God defines impute as esteeming someone righteous or sinful.You might want to look up what imputed means.
Isa 53:34
He is despised and rejected of men; a man of sorrows, and acquainted with grief: and we hid as it were our faces from him; he was despised, and we esteemed him not. Surely he hath borne our griefs, and carried our sorrows: yet we did esteem him stricken, smitten of God, and afflicted.
As the prophecy and teaching of Scripture plainly says, without any opposition being made, only men imputes Jesus with sin, and smitten of God, as by law.
Jesus was not a blasphemer cursed of God on a tree.
Mankind has neither the means or authority to impute anything to God.
Not so that God justifies it, but is done nonethess by men that justify themselves. Even as them that falsely accused, struck, afflicted, and smote Jesus as by law of blasphemy. They all believed they were slaying a blasphemer by law and will of God:
Mar 14:64
Ye have heard the blasphemy: what think ye? And they all condemned him to be guilty of death.
Isa 53:34
Yet we did esteem him stricken, smitten of God, and afflicted.
And not only the accusers, but all at the cross believed Jesus was a blasphemer as accused, condemned, and crucified. And imputed God with slaying Him as by law.
Lev 24:16
And he that blasphemeth the name of the LORD, he shall surely be put to death, and all the congregation shall certainly stone him: as well the stranger, as he that is born in the land, when he blasphemeth the name of the LORD, shall be put to death.
We see, that if we execute the law of God as commanded, then God Himself is the slayer by law. Therefore, if any man is executed as by law, whether innocent or guilty, then God is imputed to be the executioner, and so smitten of God.
They all believed, and all His disciples, that He was not the Son of God hanging on a cross, and so was 'legally' cursed and smitten by God.