For if by the transgression of the one, death reigned through the one, much more those who receive the abundance of grace and of the gift of righteousness will reign in life through the One, Jesus Christ. We come to the 13th thing which occurs the moment we trust in Christ for salvation.
Imputation is an important part of salvation.
It is not really difficult to understand, but it is one of those aspects of salvation that is rarely spoken about. There are two imputations spoken of in this passage. The first is the imputation of sin. When Adam was given the command in the garden of Eden to not eat of the tree of the knowledge of good and evil, he stood in our place, as our representative. When he disobeyed God, we disobeyed God through him because he was our representative.