As I attempt to go through the Westminster Confession of Faith and try to find harmony with Roman Catholicism, I realize how futile the effort is and how much better others are at it. The blog linked on my sidebar "Called To Communion" does just this. It is written by Reformed converts to Catholicism who are very well educated theology guys. They focus on a kind of Thomistic, closest-to-Reformed-theology-possible-within-magesterial-teaching approach and show Roman Church Teaching from a Protestant perspective. It's kind of like Peter Kreeft.
I really like the blog and it is clarifying alot for me.
Their blog on assurance was very helpful: http://www.calledtocommunion.com/2009/08/st-thomas-aquinas-on-assurance-of-salvation/
and I'm trying to get through their series on St. Thomas Aquinas and the Council of Trent:
I find whenever I read their blogs or the quotes they have from Aquinas, it reassures me in my Catholicism to the point where I continually promise myself that one day I will force myself through all of Aquinas' theology and be better for it.