a. We are born in the image of Adam after the Fall, We share his original sin by real imputation and his sin nature by genetic transmission. Thus we share his spiritual death, His sin is our sin, his sin nature our sin nature, his condemnation our condemnation. Rom. 5:14.
b. Christ is in the image of Adam before the fall.
c. Since Jesus was born of a virgin, there is no reception of a sin nature or imputation of AOS.
d. God the Father imputed all our sins to Christ on the cross, Rom. 5:15.
The result then is that man is declared righteous, he is not made righteous, sin is not overlooked, it is not just as if I had never sinned. He is declared by God to be righteous not because of what he is or will be but solely because he possesses the righteousness of Christ.
http://deanbible.org/Media/Doctrines/H-N/Imputation%20and%20Justification.pdf
Great resources.
Here’s another for those who doubt portions of Scripture.
1Jn 5:9-12
(9) If we receive the witness of men, the witness of God is greater: for this is the witness of God which he hath testified of his Son.
(10) He that believeth on the Son of God hath the witness in himself: he that believeth not God hath made him a liar; because he believeth not the record that God gave of his Son.
(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.