Tim Challies has an excellent post today on why he is not roman catholic.
He writes with backbone:
"Rome has a gospel but not the gospel and, in reality,
their gospel damns not saves because it explicitly denies that
justification comes by grace alone through faith alone in Christ alone.
Rome accurately understands the Protestant position and unapologetically anathematizes it."
And with balance:
"I joyfully affirm, of course, that there are true believers within
Catholicism and that what is true of Rome’s official doctrine is not
necessarily true of all of her adherents."
It's definately a good read, full article here