ROME, Italy — Forget such lofty aspirations as ridding the Church of child abusers or clamping down on financial corruption, Pope Francis’s biggest obstacle in reforming the Catholic Church comes down to a tiny round gluten-rich Styrofoam-tasting wafer.

The Blessed Eucharist, Holy Communion, the breaking of bread, panis triticeus, the host with the most—whatever Catholics call the thin round wafer made of unleavened wheat, the sacrament of the Eucharist is the culminating point of any Catholic mass. And, according to Catholic teaching, the most important of the seven sacraments.

Taking communion is when Catholics accept the ultimate sacrifice made for them—the body and blood of Christ who died for their sins—preferably on an empty stomach and with a clear conscience in a sin-free state of grace. In some Catholic families (disclaimer: like the one I grew up in), Saturday night confession was a pretty good way to ensure one could still be free of sin by Sunday morning mass (or in some cases, confession was followed directly by Saturday night mass in lieu of Sunday, just to be safe).