When I had decided to become Catholic, I was still living in student housing at Southeastern. I had a few weeks after classes had started at Southeastern before I moved up north to go to Franciscan. I was, if I can use the word, flooded with emails and Facebook messages concerning my conversion. Some people were curious, quite a few more were "concerned", and a few just went straight for the "You're going to hell" statements.
The "You're going to hell" crowd almost always brought up the doctrine of sola fide. This is one that I had more readily accepted during my time at Southeastern. However, I began to question it when I looked more carefully at the common proof-texts. I took a class on James and I was uncomfortable with the professor's conclusion that James 2:24 isn't really talking about "faith alone" - James really means something different. Or, the usual Eph 2:8 quote. I did an exegesis for an NT elective class of Eph 2:1-10. I've always thought it odd that Eph 2:8-9 are quoted as if that's the end of Paul's thought. The source I cited in my paper on this verse, A. Skivington Wood, stated: “this is by no means a subsidiary postscript to the paragraph. It is the outcome of the whole.” Why is Paul talking about these "good works" (dear lord, not works!) if sola fide is it? Of course, there are about a million different exegetical arguments for what Paul really means - but I find that the Catholic answer satisfies my questions of the text.
But - what really confused me about sola fide is not necessarily the exegetical arguments. Rather, the rhetoric of sola fide is not that faith alone saves - but that one must acknowledge that faith alone saves. Catholics have faith, so this would certainly be an odd doctrine to use in order to oppose Catholicism. Rather, proponents of sola fide have to admit that what they really mean is that one has to believe in the doctrine of sola fide.