The church is vague about what types of ‘sins’ will keep you out of heaven. They utilize this ambiguity in a way to keep your mind thinking constantly about ALL your actions.
“…I cannot tell you all the things whereby ye may commit sin for there are divers ways & means even so many that I cannot number them but this much I can tell you that if ye do not watch yourselves & your thoughts & your words & your deeds & observe to keep the commandments of God & continue in the faith of what ye have heard concerning the coming of our Lord even unto the end of your lives ye must perish & now re O man remember & perish not—”
The Handwritten Book of Mormon (West Valley City, UT: Dan Wees, August 2017), 207 (Mosiah 4:29-30).
This type of instruction is so unclear that even the most devout members can never be certain if they’re doing good enough at any given time.