http://www.christianforums.com/t7829613-6/#post65914408
What did Paul receive and pass on to the Corinthians when he first came to them?
1 Corinthians 15:1-3a
Now, brothers and sisters, I want to remind you of the gospel I preached to you, which you received and on which you have taken your stand. By this gospel you are saved, if you hold firmly to the word I preached to you. Otherwise, you have believed in vain.
For what I received I passed on to you as of first importance...
Galatians 1:11-12
I want you to know, brothers and sisters, that the gospel I preached is not of human origin. I did not receive it from any man, nor was I taught it; rather, I received it by revelation from Jesus Christ.
The revelation that Paul received he passed on to the Corinthians when they were unbelievers. You cannot deny this. If it was the case that Paul was (in the letter) telling the now believing Corinthians about Christ's death for their's and Paul's sins, why write and specify the point in time when when he preached to them when they were unbelievers? Paul could be accused of ambiguity if, in reminding them of what he received by revelation which he before preached to them, he is actually telling them what is the case now. Reminding someone of what was said by indirectly quoting is confusing, but the tenability of your theology rests on just that.