And I think some Roman Catholics take venial sin too lightly and dwell on whether a sin is mortal or venial way too much.
Consider the sheer number of posts on this website asking whether such-and-such sin is mortal or venial. If a sin bother’s someone enough to ask on a public website, it should probably be taken to the confessional anyway.
In response to the original post, I’ll cite the following verse:
But I say to you that everyone who is angry with his brother shall be liable to judgment; whoever insults his brother shall be liable to the council, and whoever says, “You fool!” shall be liable to the Hell of fire. (Matthew 5:22, NRSV-CE)
Matthew 5:22 records the words of The Lord himself as he speaks about what seems to be a relative gradation of sins. The sixteenth century theologian St. Francis De Sales notes that of the three sins listed, only the third sort of offense is punished with Hell. Sins of lesser gravity do not expose the sinner to the immediate possibility of hell yet they do leave the sinner open to God’s judgment. Christ’s own words seem to compliment St. John’s doctrine of deady and non-deadly sin in 1 John 5:15-16 as many other posters have cited.
-Tim-