When I became a Christian I was reassured by CS Lewis's statement in Mere Christianity that there were many theories of the atonement of Christ, but the important thing was not the theory but the thing itself: that it worked, not how it worked.
I was reassured over the following years because the theories, or accounts of causality, related to the atonement which I encountered and with which I engaged with were all significantly deficient.
Either they did not make logical sense, or else they failed to explain that which needed to be explained.
The only 'solution' seemed to be to place mysterious black boxes at strategic junctions in the argument.
Well, in my explorations of Mormon theology I have, I think, now come across an account of the Atonement (or else creatively-misunderstood one!) which 'covers all the bases' so far as I am concerned
(By the way, I really like the way that Blake Ostler does philosophy - I find it very congenial and convincing. My kind of philosopher! Here he is at work:
I watched this lecture just last night and was absolutely gripped.
I was both surprised, and not-at-all suprised, that Ostler is an 'amateur' who makes his living as an attorney and not by teaching philosophy - that is probably an essential in order to do real philosophy (i.e. for the right reasons) these days.)
I doubt whether many people could be bothered to plough-through an account of the atonement as I understand it now - but what I found interesting about all this was retrospectively to identify the assumptions which had been blocking my understanding.
The first background blocking assumption was that human souls/ spirits were created at conception/ birth - but when I assumed that our souls had pre-existence, then the possibility arose that we had chosen mortal life on earth (behind a veil of forgetfulness) - which voluntary act solves one class of problems - for example explaining how those born before Christ may be saved (i.e. because they knew, pre-mortally but not explicitly, that Christ would be coming).
The other false/ blocking assumption was that the atonement of Christ's birth and death was wholly about us, necessary for the benefit of humans alone - whereas I now believe that the process was also necessary for Christ: incarnate mortality was profoundly 'educative', and the way in which He learned by experience that which he needed to learn in order to save us.
When Christ's sufferings are seen as voluntarily undertaken and empathically-motivated, and that Christ as a personage was changed by His sufferings, permanently expanded in His understanding - then it all seems to make logical sense to me: for the first time.
So the Atonement was for us; but was undertaken by Christ in order to become able to save us.