Hierarchy of Sins?

Kaimi’s post on gay marriage prompted some thoughts on the hierarchy of sin. Some Southern Baptist friends once told me that all sins were equal in God’s eyes. Mormon theology has some similar strains. We are taught that no unclean thing can enter into the kingdom of God, and presumably any sin makes one unclean. Nevertheless, the scriptures indicate a hierarchy of sin. For example, Matthew 12:31 explains, “All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men.” Murder generally comes next in the hierarchy. D&C 132:27. Unchastity is next. Alma 39:3-5 (Alma speaking to Corianton):

And this is not all, my son. Thou didst do that which was grievous unto me; for thou didst forsake the ministry, and did go over into the land of Siron among the borders of the Lamanites, after the harlot Isabel. Yea, she did steal away the hearts of many; but this was no excuse for thee, my son. Thou shouldst have tended to the ministry wherewith thou wast entrusted. Know ye not, my son, that these things are an abomination in the sight of the Lord; yea, most abominable above all sins save it be the shedding of innocent blood or denying the Holy Ghost?

Two thoughts about this:

(1) My sense is that this hierarchy explains widespread opposition to gay marriage among Mormons better than any other principle. Mormons do not generally believe that all sins should be illegal, but this sin seems particularly grievous. (That said, it doesn’t explain anything about my views on the topic of gay marriage, but that is the subject for another post.)

(2) I wonder how far down this hierarchy goes? And what is the principle that determines where a sin falls in the hierarchy? Certainly, there are some actions that get harsher treatment than others in Church disciplinary proceedings, but this does not necessarily correspond to the seriousness of the sin to the individual’s spirituality. For example, speaking against Church leaders is bad, bad, bad in the eyes of the Church and may subject the speaker to discipline, but being uncharitable or refusing to share with the poor is not punished by the Church at all.