But Christ has indeed been raised from the dead, the firstfruits of those who have fallen asleep. For since death came through a man, the resurrection of the dead comes also through a man. For as in Adam all die, so in Christ all will be made alive. 23 But each in turn: Christ, the firstfruits; then, when he comes, those who belong to him.
An inverse mapping of any function reverses the direction of the assignment of the function. In the case that the original function is one-to-one, the inverse mapping will also be a function with the domain and codomain interchanged.
Through the sin of Adam, all people are condemned for eternity. We cannot escape our inherited imperfection. Let's define the "Adam life function" to act on people. This function has output death for all inputs. However, Christ inverts the total condemnation of people through his death and resurrection. This acts as a sort of inverse to the "Adam life function;" the "Christ death function" acts on all people and brings life to those who believe. This is not truly an inverse function--it is more of a negation--the negation of Adam (man) is Christ and the negation of life is death. It is ironic that to give eternal life to people whose lives are undeserving, Christ had to die.