Elizabeth Scalia has written a deplorable post at the site "Aleteia", in which she works herself into a state of agnosticism about Catholic doctrine on the reception of communion. Her post is depressing, and represents pretty well how we sin by tricking ourselves into not knowing what we really ought to know.
Ms. Scalia, can I introduce you to something called a Catechism?
You too can own one of these nifty little books! It has all the important stuff worked out! No sentimental handwringing required! Give it a try. I bet you'll like it.