Originally posted by @mister-moggy
it is a given in the ot that the christ was the creater of creation and existed before creation and is part of the truine god theory.
it is given that the christ mission was to atone for the sins of man thru death and resurrection, etc.
since adam was the only man alive after creation and adam sinned why did not the christ go thru the atonement to save "all mankind" at that time ?.
It is an interesting question.
The basis for all of this, though, is that Christ does not come solely to provide atonement in the most minimal form.
He came to transform the world and to bring the Graces of God into the world, and that is part of the great sacrifice for the atonement of mankind.
We know from many different Bible passages that salvation, rationality, and God's love extends to people who are beyond the scope of the nation of Israel and who lived in ignorance. While it is far less than ideal to depend on mercy coming from outside of the Covenant, it is not absolutely essential for there to be reconition of the atonement for salvation.
So, one of the answers to your riddle is just viewing Christ's Sacrifice as also something meant to bring graces in addition to salvation.
Generally speaking, in Christianity, the most important thing to remember is that it is meant to always have a holistic understanding of the content, and to not try to isolate single aspects of it and remove it from the framework of the whole.