I find the concept of grave sins in the Roman church fascinating, not because I agree with the concept, but it actually mirrors so much of why I left the non-denominational and Baptist worlds.
Based on my readings,through the course of history that the Roman Catholic church has developed a list of grave sins that require individuals to not receive communion. If individuals do not voluntarily refrain from going forward to receive communion, the local priest has responsibility and authority to not offer communion. This often prevents divorced and re-married individuals from receiving communion. Also, according to some news reports, local priests have been pressured to not offer communion to politicians based on their votes and political views.
By the letter of traditional beliefs, all sin separates us from God. But, over church history, the concept of grave sins has not only permeated Roman Catholic beliefs, but has also permeated traditional Baptist beliefs. The list has often changed. As a child growing up in the South in the Baptist world, consuming alcohol was considered a grave sin. In some areas this traditional prohibition has subsided, but in other areas it is still strong. In the 1990’s,as my own life was in chaos, the influences of Promise Keepers led to the belief that family problems were the result of a man’s failure to lead, leading to an implied belief that a failure to lead was a grave sin. In the past few years it seems as though financial mis-management as preached by Dave Ramsey has become the latest of grave sins. I may disagree with the Catholic list, but at least it is fairly consistent. The Baptist and non-denominational list continually change.
A major problem with a list of grave sins is that it is a slippery slope towards legalism. I may disagree with the Roman list, but at least it has been developed over history and very slowly changes. In the Baptist and non-denominational worlds, the lists of grave sins constantly change.
I believe that all sin separates us from God, but that no sin separates us from communion with God. And, since no sin separates us from communion with God, no list of sins should separate us from participating in the Eucharist.