Here is what it says in Eva's link above:
"Mr. Lincoln made an interesting argument regarding sin shortly before the Civil War. “Isaac Cogdal, who had known Lincoln from the time of the New Salem period, recalled a discussion on religion in Lincoln’s office in 1859. Herndon was in the office at the time.
...Lincoln expressed himself in about these words: ‘all that was lost by the transgression of Adam was made good by the atonement; all that was lost by the fall was made good by the sacrifice...’"
That sounds like he believed in Christ, unless he was speaking of some other atonement that I know nothing of.
But according to this article, Isaac Cogdal is not particularly trustworthy:
http://quod.lib.umich.edu/j/jala/2629860...w=fulltext
After doing a little more research, I find that the writer of the article on Isaac Cogdal, C.A. Tripp, wrote a book on Lincoln's supposed gayness.
http://usgovinfo.about.com/od/thepreside...gayabe.htm
(OK, I've had enough of this. Too many alleged historians and writers with their own agendas.)