Was Jesus Crucified for our Atonement?

Was Jesus Crucified for our Atonement?

In order to continue the discussion with Christians, we put forward two following questions, one is historical, and the other is theological.
The first question is:
Did Jesus (PBUH) die on the cross, as the Gospels mention and the contemporary Christian sects agree?
The second question, which is related to the first – we ask it just for the sake of argument – is, assuming that Jesus died on the cross:
Was he crucified to atone us and humanity? Following these two questions, many other questions will arise.
What is the salvation from; is it from the Hellfire or from the world’s troubles and miseries?
Is it a salvation from our parents’ (Adam and Eve) sins only, or all of our sins?
Is it conditional or is it a love gift from Allah (S.W) and his Christ, which is far great to be reciprocated?
Is the salvation for the Jews only, to whom Jesus (Peace be upon him) was sent, or for the whole human beings, which were born full of sins? We will answer these questions and others, in this book, concluding them in one question, was Jesus crucified for our atonement? We will answer these questions objectively, logically, and scientifically; searching the pages of the Christian Holy Bible, taking our minds, our instincts and our reasoning as the judge , considering the professes of the history and the wisdom of Christianity’s wise men as evidence.