he phrase "in Adam all die" from
1 Corinthians 15:22 means that death, both physical and spiritual, entered the world through Adam's sin, and this condition was passed on to all humanity. This theological concept, related to original sin, explains that all people are subject to death because they are descended from Adam, the first man. The full verse,
"For as in Adam all die, so in Christ all will be made alive,", continues to state that just as all humanity is affected by Adam's sin, all who are in Christ will be made alive through his resurrection
Imputation means to ascribe (righteousness, guilt, etc.) to someone by virtue of a similar quality in another.
How?

.... God says so and therefore it is. Psalm 51:5, which is King David's lament. It is interpreted to mean that all people are born with a sinful nature, inherited from the first human sin
Phrasing by ChatGPT